Stilbene derivatives and their use for binding and imaging amyloid plaques

ABSTRACT

This invention relates to a method of imaging amyloid deposits and to labeled compounds, and methods of making labeled compounds useful in imaging amyloid deposits. This invention also relates to compounds, and methods of making compounds for inhibiting the aggregation of amyloid proteins to form amyloid deposits, and a method of delivering a therapeutic agent to amyloid deposits.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. Pat. No. 7,807,135, filedDec. 19, 2005, which claims the benefit of U.S. Provisional ApplicationNo. 60/686,395, filed Jun. 2, 2005 and U.S. Provisional Application No.60/636,696, filed Dec. 17, 2004.

Part of the work performed during development of this invention utilizedU.S. Government funds. The U.S. Government has certain rights in thisinvention under grant number AG021868, awarded by the NationalInstitutes of Health.

TECHNICAL FIELD

This invention relates to novel bioactive compounds, methods ofdiagnostic imaging using radiolabeled compounds, and methods of makingradiolabeled compounds.

BACKGROUND

Alzheimer's disease (AD) is a progressive neurodegenerative disordercharacterized by cognitive decline, irreversible memory loss,disorientation, and language impairment. Postmortem examination of ADbrain sections reveals abundant senile plaques (SPs) composed ofamyloid-β (Aβ) peptides and numerous neurofibrillary tangles (NFTs)formed by filaments of highly phosphorylated tau proteins (for recentreviews and additional citations see Ginsberg, S. D., et al., “MolecularPathology of Alzheimer's Disease and Related Disorders,” in CerebralCortex: Neurodegenerative and Age-related Changes in Structure andFunction of Cerebral Cortex, Kluwer Academic/Plenum, N.Y. (1999), pp.603-654; Vogelsberg-Ragaglia, V., et al., “Cell Biology of Tau andCytoskeletal Pathology in Alzheimer's Disease,” Alzheimer's Disease,Lippincot, Williams & Wilkins, Philadelphia, Pa. (1999), pp. 359-372).

Amyloidosis is a condition characterized by the accumulation of variousinsoluble, fibrillar proteins in the tissues of a patient. An amyloiddeposit is formed by the aggregation of amyloid proteins, followed bythe further combination of aggregates and/or amyloid proteins. Formationand accumulation of aggregates of β-amyloid (Aβ) peptides in the brainare critical factors in the development and progression of AD.

In addition to the role of amyloid deposits in Alzheimer's disease, thepresence of amyloid deposits has been shown in diseases such asMediterranean fever, Muckle-Wells syndrome, idiopathetic myeloma,amyloid polyneuropathy, amyloid cardiomyopathy, systemic senileamyloidosis, amyloid polyneuropathy, hereditary cerebral hemorrhage withamyloidosis, Down's syndrome, Scrapie, Creutzfeldt-Jacob disease, Kuru,Gerstamnn-Straussler-Scheinker syndrome, medullary carcinoma of thethyroid, Isolated atrial amyloid, β₂-microglobulin amyloid in dialysispatients, inclusion body myositis, β₂-amyloid deposits in muscle wastingdisease, and Islets of Langerhans diabetes Type II insulinoma.

The fibrillar aggregates of amyloid peptides, Aβ₁₋₄₀ and Aβ₁₋₄₂, aremajor metabolic peptides derived from amyloid precursor protein found insenile plaques and cerebrovascular amyloid deposits in AD patients (Xia,W., et al., J. Proc. Natl. Acad. Sci. U.S.A. 97:9299-9304 (2000)).Prevention and reversal of Aβ plaque formation are being targeted as atreatment for this disease (Selkoe, D., J. JAMA 283:1615-1617 (2000);Wolfe, M. S., et al., J. Med. Chem. 41:6-9 (1998); Skovronsky, D. M.,and Lee, V. M., Trends Pharmacol. Sci. 21:161-163 (2000)).

Familial AD (FAD) is caused by multiple mutations in the A precursorprotein (APP), presenilin 1 (PS1) and presenilin 2 (PS2) genes(Ginsberg, S. D., et al., “Molecular Pathology of Alzheimer's Diseaseand Related Disorders,” in Cerebral Cortex: Neurodegenerative andAge-related Changes in Structure and Function of Cerebral Cortex, KluwerAcademic/Plenum, N.Y. (1999), pp. 603-654; Vogelsberg-Ragaglia, V., etal., “Cell Biology of Tau and Cytoskeletal Pathology in Alzheimer'sDisease,” Alzheimer's Disease, Lippincot, Williams & Wilkins,Philadelphia, Pa. (1999), pp. 359-372).

While the exact mechanisms underlying AD are not fully understood, allpathogenic FAD mutations studied thus far increase production of themore amyloidogenic 42-43 amino-acid long form of the Aβ peptide. Thus,at least in FAD, dysregulation of Aβ production appears to be sufficientto induce a cascade of events leading to neurodegeneration. Indeed, theamyloid cascade hypothesis suggests that formation of extracellularfibrillar Aβ aggregates in the brain may be a pivotal event in ADpathogenesis (Selkoe, D. J., “Biology of β-amyloid Precursor Protein andthe Mechanism of Alzheimer's Disease,” Alzheimer's Disease, LippincotWilliams & Wilkins, Philadelphia, Pa. (1999), pp. 293-310; Selkoe, D.J., J. Am. Med. Assoc. 283:1615-1617 (2000); Naslund, J., et al., J. Am.Med. Assoc. 283:1571-1577 (2000); Golde, T. E., et al., Biochimica etBiophysica Acta 1502:172-187 (2000)).

Various approaches in trying to inhibit the production and reduce theaccumulation of fibrillar Aβ in the brain are currently being evaluatedas potential therapies for AD (Skovronsky, D. M. and Lee, V. M., TrendsPharmacol. Sci. 21:161-163 (2000); Vassar, R., et al., Science286:735-741 (1999); Wolfe, M. S., et al., J. Med. Chem. 41:6-9 (1998);Moore, C. L., et al., J. Med. Chem. 43:3434-3442 (2000); Findeis, M. A.,Biochimica et Biophysica Acta 1502:76-84 (2000); Kuner, P., Bohrmann, etal., J. Biol. Chem. 275:1673-1678 (2000)). It is therefore of interestto develop ligands that specifically bind fibrillar Aβ aggregates. Sinceextracellular SPs are accessible targets, these new ligands could beused as in vivo diagnostic tools and as probes to visualize theprogressive deposition of Aβ in studies of AD amyloidogenesis in livingpatients.

To this end, several interesting approaches for developing fibrillar Aβaggregate-specific ligands have been reported (Ashburn, T. T., et al.,Chem. Biol. 3:351-358 (1996); Han, G., et al., J. Am. Chem. Soc.118:4506-4507 (1996); Klunk, W. E., et al., Biol. Psychiatry 35:627(1994); Klunk, W. E., et al., Neurobiol. Aging 16:541-548 (1995); Klunk,W. E., et al., Society for Neuroscience Abstract 23:1638 (1997); Mathis,C. A., et al., Proc. XIIth Intl. Symp. Radiopharm. Chem., Uppsala,Sweden:94-95 (1997); Lorenzo, A. and Yankner, B. A., Proc. Natl. Acad.Sci. U.S.A. 91:12243-12247 (1994); Zhen, W., et al., J. Med. Chem.42:2805-2815 (1999)). The most attractive approach is based on highlyconjugated chrysamine-G (CG) and Congo red (CR), and the latter has beenused for fluorescent staining of SPs and NFTs in postmortem AD brainsections (Ashburn, T. T., et al., Chem. Biol. 3:351-358 (1996); Klunk,W. E., et al., J. Histochem. Cytochem. 37:1273-1281 (1989)). Theinhibition constants (K_(i)) for binding to fibrillar Aβ aggregates ofCR, CG, and 3′-bromo- and 3′-iodo derivatives of CG are 2,800, 370, 300and 250 nM, respectively (Mathis, C. A., et al., Proc. XIIth Intl. Symp.Radiopharm. Chem., Uppsala, Sweden:94-95 (1997)). These compounds havebeen shown to bind selectively to Aβ (1-40) peptide aggregates in vitroas well as to fibrillar Aβ deposits in AD brain sections (Mathis, C. A.,et al., Proc. XIIth Intl. Symp. Radiopharm. Chem., Uppsala, Sweden:94-95(1997)).

There are several potential benefits of imaging Aβ aggregates in thebrain. The imaging technique will improve diagnosis by identifyingpotential patients with excess Aβ plaques in the brain; therefore, theymay be likely to develop Alzheimer's disease. It will also be useful tomonitor the progression of the disease. When anti-plaque drug treatmentsbecome available, imaging Aβ plaques in the brain may provide anessential tool for monitoring treatment. Thus, a simple, noninvasivemethod for detecting and quantitating amyloid deposits in a patient hasbeen eagerly sought. Presently, detection of amyloid deposits involveshistological analysis of biopsy or autopsy materials. Both methods havedrawbacks. For example, an autopsy can only be used for a postmortemdiagnosis.

The direct imaging of amyloid deposits in vivo is difficult, as thedeposits have many of the same physical properties (e.g., density andwater content) as normal tissues. Attempts to image amyloid depositsusing magnetic resonance imaging (MRI) and computer-assisted tomography(CAT) have been disappointing and have detected amyloid deposits onlyunder certain favorable conditions. In addition, efforts to labelamyloid deposits with antibodies, serum amyloid P protein, or otherprobe molecules have provided some selectivity on the periphery oftissues, but have provided for poor imaging of tissue interiors.

Potential ligands for detecting Aβ aggregates in the living brain mustcross the intact blood-brain barrier. Thus brain uptake can be improvedby using ligands with relatively smaller molecular size (compared toCongo Red) and increased lipophilicity. Highly conjugated thioflavins (Sand T) are commonly used as dyes for staining the Aβ aggregates in theAD brain (Elhaddaoui, A., et al., Biospectroscopy 1:351-356 (1995)).

A highly lipophilic tracer, [¹⁸F]FDDNP, for binding both tangles (mainlycomposed of hyperphosphorylated tau protein) and plaques (containing Aβprotein aggregates) has been reported. (Shoghi-Jadid K, et al., Am JGeriatr Psychiatry. 2002; 10:24-35). Using positron-emission tomography(PET), it was reported that this tracer specifically labeled deposits ofplaques and tangles in nine AD patients and seven comparison subjects.(Nordberg A. Lancet Neurol. 2004; 3:519-27). Using a novelpharmacokinetic analysis procedure called the relative residence time ofthe brain region of interest versus the pons, differences between ADpatients and comparison subjects were demonstrated. The relativeresidence time was significantly higher in AD patients. This is furthercomplicated by an intriguing finding that FDDNP competes with someNSAIDs for binding to Aβ fibrils in vitro and to Aβ plaques ex vivo(Agdeppa E D, et al. 2001; Agdeppa E D, et al., Neuroscience. 2003;117:723-30).

Imaging β-amyloid in the brain of AD patients by using a benzothiazoleaniline derivative, [¹¹C]6-OH-BTA-1 (also referred to as [¹¹C]PIB), wasrecently reported. (Mathis C A, et al., Curr Pharm Des. 2004;10:1469-92; Mathis C A, et al., Arch. Neurol. 2005, 62:196-200.).Contrary to that observed for [¹⁸F]FDDNP, [¹¹C]6-OH-BTA-1 bindsspecifically to fibrillar Aβ in vivo. Patients with diagnosed mild ADshowed marked retention of [¹¹C]6-OH-BTA-1 in the cortex, known tocontain large amounts of amyloid deposits in AD. In the AD patientgroup, [¹¹C]6-OH-BTA-1 retention was increased most prominently in thefrontal cortex. Large increases also were observed in parietal,temporal, and occipital cortices and in the striatum. [¹¹C]6-OH-BTA-1retention was equivalent in AD patients and comparison subjects in areasknown to be relatively unaffected by amyloid deposition (such assubcortical white matter, pons, and cerebellum). Recently, another ¹¹Clabeled Aβ plaque-targeting probe, a stilbene derivative-[¹¹C]SB-13, hasbeen studied. In vitro binding using the [³H]SB-13 suggests that thecompound showed excellent binding affinity and binding can be clearlymeasured in the cortical gray matter, but not in the white matter of ADcases. (Kung M-P, et al., Brain Res. 2004; 1025:98-105. There was a verylow specific binding in cortical tissue homogenates of control brains.The Kd values of [³H]SB-13 in AD cortical homogenates were 2.4±0.2 nM.High binding capacity and comparable values were observed (14-45 pmol/mgprotein) (Id.). As expected, in AD patients [¹¹C]SB-13 displayed a highaccumulation in the frontal cortex (presumably an area containing a highdensity of Aβ plaques) in mild to moderate AD patients, but not inage-matched control subjects. (Verhoeff N P, et al., Am J GeriatrPsychiatry. 2004; 12:584-95).

It would be useful to have a noninvasive technique for imaging andquantitating amyloid deposits in a patient. In addition, it would beuseful to have compounds that inhibit the aggregation of amyloidproteins to form amyloid deposits and a method for determining acompound's ability to inhibit amyloid protein aggregation.

SUMMARY

The present invention provides novel compounds of Formulae I, II andIII.

The present invention also provides diagnostic compositions comprising aradiolabeled compound of Formula I, II or III and a pharmaceuticallyacceptable carrier or diluent.

The invention further provides a method of imaging amyloid deposits, themethod comprising introducing into a patient a detectable quantity of alabeled compound of Formula I, II or III or a pharmaceuticallyacceptable salt, ester, amide or prodrug thereof.

The present invention also provides a method for inhibiting theaggregation of amyloid proteins, the method comprising administering toa mammal an amyloid inhibiting amount of a compound Formula I, II or IIIor a pharmaceutically acceptable salt, ester, amide, or prodrug thereof.

A further aspect of this invention is directed to methods andintermediates useful for synthesizing the amyloid inhibiting and imagingcompounds of Formula I, II or III described herein.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 depicts K_(i) binding data of several compounds of the presentinvention.

DETAILED DESCRIPTION OF ILLUSTRATIVE EMBODIMENTS

In a first aspect the present invention is directed to compounds ofFormula I:

or a pharmaceutically acceptable salt or prodrug thereof, wherein:

R¹ is selected from the group consisting of:

-   -   a. NR^(a)R^(b), wherein R^(a) and R^(b) are independently        hydrogen, C₁₋₄ alkyl, (CH₂)_(d) ¹⁸F, and d is an integer between        1 and 4,    -   b. hydroxy,    -   c. C₁₋₄ alkoxy,    -   d. hydroxy(C₁₋₄)alkyl,    -   e. halogen,    -   f. cyano,    -   g. hydrogen,    -   h. nitro,    -   i. (C₁-C₄)alkyl,    -   j. Halo(C₁-C₄)alkyl, and    -   k. formyl

R^(1′) is selected from the group consisting of

-   -   a. ¹²³I, ¹²⁵I, ¹³¹I, ¹⁸F, ⁷⁶Br;    -   b. hydrogen    -   c. ¹⁸F(C₁₋₄)alkyl,    -   d. [¹⁸F(C₁₋₄)alkyl]amino,    -   e. [¹⁸F(C₁-C₄)alkyl]alkylamino    -   f. ¹⁸F(C₁-C₄)alkoxy

R² is selected from the group consisting of

-   -   i. hydroxyl, C₁₋₄Alkoxy, (C₁-C₄)-alkyloxoAlk(C₁-C₄)oxy,        (C₁-C₄)-alkyloxo(C₁-C₄)-alkyloxo(C₁-C₄)alkoxy,        (C₁-C₄)-alkyloxo(C₁-C₄)-alkyloxo(C₁-C₄)-alkyloxo(C₁-C₄)alkoxy,        carboxy(C₁-C₄)Alkyl, halo(C₁-C₄)alkoxy,        halo(C₁-C₄)-alkyloxo(C₁-C₄)alkoxy,        halo(C₁-C₄)alkyloxo(C₁-C₄)alkyloxo(C₁-C₄)-alkyloxy,        halo(C₁-C₄)alkyloxo(C₁-C₄)alkyloxo(C₁-C₄)alkyloxo(C₁-C₄)alkyloxy,        halo(C₁-C₄)alkyl, NR⁶R^(6′), phenyl(C₁-C₄)alkyl,        ¹⁸F(C₁-C₄)alkoxy, ¹⁸F(C₁-C₄)alkyloxo(C₁-C₄)alkoxy,        ¹⁸F(C₁-C₄)alkyloxo(C₁-C₄)alkyloxo(C₁-C₄)alkyloxy,        ¹⁸F(C₁-C₄)alkyloxo(C₁-C₄)alkyloxo(C₁-C₄)alkyloxo(C₁-C₄)alkyloxy,        ¹⁸F(C₁-C₄)alkyl,    -   wherein R⁶ and R^(6′) are independently selected from the group        consisting of hydrogen, hydroxy(C₁-C₄)alkyl and C₁-C₄alkyl

where q is an integer from one to 10; Z is selected from the groupconsisting of ¹⁸F, ¹⁸F substituted benzoyloxy, ¹⁸F substitutedbenzyloxy, preferably ¹⁸F-phenoxy, ¹⁸F substituted phenyl(C₁₋₄)alkyl,¹⁸F substituted (C₁₋₄)alkoxy, ¹⁸F substituted aryloxy and a ¹⁸Fsubstituted C₆₋₁₀ aryl, preferably ¹⁸F-phenyl; and R³⁰, R³¹, R³² and R³³are in each instance independently selected from the group consisting ofhydrogen, hydroxy, C₁₋₄ alkoxy, C₁₋₄ alkyl, and hydroxy(C₁₋₄)alkyl;

wherein Z, R³⁰, R³¹, R³² and R³³ are as described above;

where Y is selected from the group consisting of ¹⁸F, ¹⁸F substitutedbenzoyloxy, ¹⁸F substituted phenyl(C₁₋₄)alkyl, ¹⁸F substituted aryloxypreferably ¹⁸F-phenoxy and ¹⁸F substituted C₆₋₁₀ aryl, preferably¹⁸F-phenyl;

U is selected from the group consisting of hydrogen, hydroxy, ¹⁸F, ¹⁸Fsubstituted benzoyloxy, ¹⁸F substituted phenyl(C₁₋₄)alkyl, ¹⁸Fsubstituted aryloxy, preferably ¹⁸F-phenoxy and ¹⁸F substituted C₆₋₁₀aryl, preferably ¹⁸F-phenyl; and

R³⁴, R³⁵, R³⁶, R³⁷, R³⁸, R³⁹ and R⁴⁰ are in each instance independentlyselected from the group consisting of hydrogen, hydroxy, C₁₋₄ alkoxy,C₁₋₄ alkyl, and hydroxy(C₁₋₄)alkyl; and

R⁷ and R⁸ are in each instance independently selected from the groupconsisting of halogen, e.g. F, Cl, Br, hydrogen, hydroxy, amino,methylamino, dimethylamino, C₁₋₄ alkoxy, C₁₋₄ alkyl, andhydroxy(C₁₋₄)alkyl, wherein at least one of R⁷ and R⁸ is halogen,preferably F.

In a preferred embodiment

R¹ is independently selected from the group consisting of hydrogen,halogen, e.g. F, Cl, Br, C₁-C₄ alkyl, cyano, hydroxyl, nitro,(C₁-C₄)alkylamino, di(C₁-C₄)alkylamino, halo(C₁-C₄)alkyl, formyl, andalk(C₁-C₄)-oxy

R^(1′) is independently selected from thr group consisting of hydrogen,¹²³I, ¹²⁵I, ¹³¹I, ¹⁸F, ¹⁸F(C₁₋₄)alkyl, [¹⁸F(C₁₋₄)alkyl]amino,[¹⁸F(C₁-C₄)alkyl]alkylamino, ¹⁸F(C₁-C₄)alkoxy and ⁷⁶Br

R² is independently selected from the group consisting of hydroxyl,C₁₋₄alkoxy, (C₁-C₄)alkyloxoalk(C₁-C₄)oxy, carboxy(C₁-C₄)alkyl,halo(C₁-C₄)-alkoxy, halo(C₁-C₄)alkyloxo(C₁-C₄)alkoxy,Halo(C₁-C₄)alkyloxo(C₁-C₄)-alkyloxo(C₁-C₄)alkyloxy,halo(C₁-C₄)alkyloxo(C₁-C₄)alkyloxo(C₁-C₄)alkyloxo-(C₁-C₄)alkyloxy,halo(C₁-C₄)alkyl, NR⁶R^(6′), phenyl(C₁-C₄)alkyl, ¹⁸F(C₁-C₄)alkoxy,¹⁸F(C₁-C₄)alkyloxo-(C₁-C₄)alkoxy,¹⁸F(C₁-C₄)alkyloxo-(C₁-C₄)-alkyloxo(C₁-C₄)alkyloxy,¹⁸F(C₁-C₄)alkyloxo(C₁-C₄)alkyloxo(C₁-C₄)alkyloxo-(C₁-C₄)alkyloxy,¹⁸F(C₁-C₄)alkyl

R⁶ and R^(6′) are independently selected from the group consisting ofhydrogen, hydroxy(C₁-C₄)alkyl, and C₁-C₄alkyl,

R⁷ and R⁸ is selected from H, F, Cl or Br, wherein either R⁷ and R⁸ ishalogen.

In a further preferred embodiment

R¹ is selected from the group consisting of hydrogen, hydroxy,(C₁-C₄)alkylamino, di(C₁-C₄)alkylamino, methyl and methoxy, inparticular from hydrogen, methylamino, and dimethylamino,

R^(1′) is selected from the group consisting of hydrogen, ¹²³I, ¹²⁵I,¹³¹I and ¹⁸F, in particular from hydrogen,

R² is selected from the group consisting of hydroxy, C₁-C₄alkoxy, NR⁶,R^(6′), ¹⁸F(C₁-C₄)alkoxy, ¹⁸F(C₁-C₄)alkyloxo(C₁-C₄)alkoxy,¹⁸F(C₁-C₄)alkyloxo(C₁-C₄)alkyloxo(C₁-C₄)alkyloxy,¹⁸F(C₁-C₄)alkyloxo(C₁-C₄)alkyloxo-(C₁-C₄)alkyloxo(C₁-C₄)alkyloxy,¹⁸F(C₁-C₄)alkyl, in particular from (C₁-C₄)alkyloxo(C₁-C₄)alkoxy,¹⁸F(C₁-C₄)alkyloxo(C₁-C₄)alkyloxo(C₁-C₄)alkyloxy, and¹⁸F(C₁-C₄)alkyloxo(C₁-C₄)alkyloxo(C₁-C₄)alkyloxo(C₁-C₄)alkyloxy,

R⁶ and R^(6′) are independently selected from the group consisting ofhydrogen, hydroxy(C₁-C₄)alkyl and C₁-C₄alkyl,

R⁷ and R⁸ is selected from the group consisting of hydrogen andfluorine, wherein either R⁷ or R⁸ is fluorine.

It has been surprisingly found that stilbene derivatives which carry anadditional halogen, in particular, fluorine atom at the double bond showimproved pharmacokinetic properties and/or an increased metabolicstability and/or an increased geometrically isomeric stability anduniformity.

Preferred compounds of Formula I have the following structures:

wherein one of R⁷ and R⁸ is hydrogen, and the other is halogen.

A second aspect of the present invention is directed to compounds ofFormula II:

or a pharmaceutically acceptable salt thereof, wherein:

R¹ is selected from the group consisting of:

-   -   a. NR^(a)R^(b), wherein R^(a) and R^(b) are independently        hydrogen, C₁₋₄ alkyl, (CH₂)_(d) ¹⁸F, and d is an integer between        1 and 4, or R^(a) and R^(b) are both oxygen to form a nitro,    -   b. hydroxy,    -   c. C₁₋₄ alkoxy, and    -   d. hydroxy(C₁₋₄)alkyl;

R² is selected from the group consisting of:

where q is an integer from one to 10; Z is selected from the groupconsisting of ¹⁸F, ¹⁸F substituted benzoyloxy, ¹⁸F substituted(C₁₋₄)alkoxy, ¹⁸F substituted benzyloxy, preferably ¹⁸F-phenoxy, ¹⁸Fsubstituted phenyl(C₁₋₄)alkyl, ¹⁸F substituted aryloxy, and a ¹⁸Fsubstituted C₆₋₁₀ aryl, preferably ¹⁸F-phenyl; and R³⁰, R³¹, R³² and R³³are in each instance independently selected from the group consisting ofhydrogen, hydroxy, C₁₋₄ alkoxy, C₁₋₄ alkyl and hydroxy(C₁₋₄alkyl;

wherein Z, R³⁰, R³¹, R³² and R³³ are as described above;

where Y is selected from the group consisting of ¹⁸F, ¹⁸F substitutedbenzoyloxy, ¹⁸F substituted phenyl(C₁₋₄)alkyl, ¹⁸F substituted aryloxy,preferably ¹⁸F-phenoxy, and ¹⁸F substituted C₆₋₁₀ aryl, preferably¹⁸F-phenyl;

U is selected from the group consisting of hydrogen, hydroxy, ¹⁸F, ¹⁸Fsubstituted benzoyloxy, ¹⁸F substituted phenyl(C₁₋₄)alkyl, ¹⁸Fsubstituted aryloxy, preferably ¹⁸F-phenoxy and ¹⁸F substituted C₆₋₁₀aryl, preferably ¹⁸F-phenyl; and

R³⁴, R³⁵, R³⁶, R³⁷, R³⁸, R³⁹ and R⁴⁰ are in each instance independentlyselected from the group consisting of hydrogen, hydroxy, C₁₋₄ alkoxy,C₁₋₄ alkyl, and hydroxy(C₁₋₄)alkyl; and

R⁷ and R⁸ are in each instance independently selected from the groupconsisting of hydrogen, hydroxy, amino, methylamino, dimethylamino, C₁₋₄alkoxy, C₁₋₄ alkyl, and hydroxy(C₁₋₄)alkyl.

More preferably, the value of each of R³⁰, R³¹, R³², R³³, R³⁴, R³⁵, R³⁶,R³⁷, R³⁸, R³⁹ and R⁴⁰ is in each instance independently selected fromthe group consisting of hydrogen, hydroxy, amino, methylamino,dimethylamino and methoxy.

Preferably, R² is either in the meta or para position relative to theethylene bridge.

When R² is

the preferred value for R³⁰, R³¹, R³² and R³³ in each instance ishydrogen, and Z is ¹⁸F. Useful values of q include integers from one toten. Preferably, q is an integer from 2 to 5. More preferably, the valueof q is 3 or 4.

Preferred embodiments of Formula II include the following structureswherein R^(a) and R^(b) are independently hydrogen or methyl, preferablyat least one of R^(a) and R^(b) is methyl:

and X is ¹⁸F.

A preferred series of compounds of Formula II include ¹⁸F labeledpolyethyleneglycol(PEG)-stilbene derivatives having the followingstructures:

wherein, q is an integer from one to ten. More preferred compoundsinclude those where q is equal to:two,

three,

or four,

In this series of compounds, ¹⁸F is linked to the stilbene through a PEGchain, having a variable number of ethoxy groups. All of the fluorinatedstilbenes displayed high binding affinities in an assay using postmortemAD brain homogenates (K_(i)=2.9-6.7 nM). As shown in Schemes 1-3 herein,radiolabeling was successfully performed by a substitution of themesylate group of 10a-d by [¹⁸F]fluoride giving the target compounds[¹⁸F]12a-d (EOS, specific activity, 900-1,500 Ci/mmol; radiochemicalpurity >99%). In vivo biodistribution of these ¹⁸F ligands in normalmice exhibited excellent brain penetrations and rapid washouts after aniv injection (6.6-8.1 and 1.2-2.6% dose/g at 2 min and 60 min,respectively). Autoradiography of postmortem AD brain sections of[¹⁸F]12a-d confirmed the specific binding related to the presence of Aβplaques. In addition, in vivo plaque labeling can be clearlydemonstrated with these ¹⁸F labeled agents in transgenic mice (Tg2576),a useful animal model for Alzheimer's disease.

The present invention is also directed to compounds of Formula III:

wherein n is an integer between 1 and 4, R⁷ and R⁸ are each as describedabove, and R⁴¹ is selected from the group consisting of hydroxy andNR^(a)R^(b), wherein R^(a) and R^(b) are independently hydrogen, C₁₋₄alkyl or R^(a) and R^(b) are both oxygen to form a nitro.

Preferably, n is one, and R⁴¹ is hydroxy, methylamino or dimethylamino.

Preferable values under the scope of C₆₋₁₀ aryl include phenyl, naphthylor tetrahydronaphthyl. Preferable values of under the scope ofheteroaryl include thienyl, furyl, pyranyl, pyrrolyl, pyridinyl,indolyl, and imidazolyl. Preferable values under the scope ofheterocycle include piperidinyl, pyrrolidinyl, and morpholinyl.

The compounds of Formulae I, II and III may also be solvated, especiallyhydrated. Hydration may occur during manufacturing of the compounds orcompositions comprising the compounds, or the hydration may occur overtime due to the hygroscopic nature of the compounds. In addition, thecompounds of the present invention can exist in unsolvated as well assolvated forms with pharmaceutically acceptable solvents such as water,ethanol, and the like. In general, the solvated forms are consideredequivalent to the unsolvated forms for the purposes of the presentinvention.

It is also to be understood that the present invention is considered toinclude stereoisomers, such as both cis and trans isomers of thestilbene-type compounds. Further included are: optical isomers, e.g.mixtures of enantiomers as well as individual enantiomers anddiastereomers, which arise as a consequence of structural asymmetry inselected compounds of Formula I, II or III.

When any variable occurs more than one time in any constituent or inFormula I, II or III its definition on each occurrence is independent ofits definition at every other occurrence. Also combinations ofsubstituents and/or variables are permissible only if such combinationsresult in stable compounds.

The term “alkyl” as employed herein by itself or as part of anothergroup refers to both straight and branched chain radicals of up to 8carbons, preferably 6 carbons, more preferably 4 carbons, such asmethyl, ethyl, propyl, isopropyl, butyl, t-butyl, and isobutyl.

The term “alkoxy” is used herein to mean a straight or branched chainalkyl radical, as defined above, unless the chain length is limitedthereto, bonded to an oxygen atom, including, but not limited to,methoxy, ethoxy, n-propoxy, isopropoxy, and the like. Preferably thealkoxy chain is 1 to 6 carbon atoms in length, more preferably 1-4carbon atoms in length.

The term “monoalkylamine” as employed herein by itself or as part ofanother group refers to an amino group which is substituted with onealkyl group as defined above.

The term “dialkylamine” as employed herein by itself or as part ofanother group refers to an amino group which is substituted with twoalkyl groups as defined above.

The term “halo” or “halogen” employed herein by itself or as part ofanother group refers to chlorine, bromine, fluorine or iodine, unlessdefined otherwise in specific uses in the text and/or claims.

The term “haloalkyl” as employed herein refers to any of the above alkylgroups substituted by one or more chlorine, bromine, fluorine or iodinewith fluorine and chlorine being preferred, such as chloromethyl,iodomethyl, trifluoromethyl, 2,2,2-trifluoroethyl, and 2-chloroethyl.

The term “aryl” as employed herein by itself or as part of another grouprefers to monocyclic or bicyclic aromatic groups containing from 6 to 12carbons in the ring portion, preferably 6-10 carbons in the ringportion, such as phenyl, naphthyl or tetrahydronaphthyl.

The term “heterocycle” or “heterocyclic ring”, as used herein exceptwhere noted, represents a stable 5- to 7-membered mono-heterocyclic ringsystem which may be saturated or unsaturated, and which consists ofcarbon atoms and from one to three heteroatoms selected from the groupconsisting of N, O, and S, and wherein the nitrogen and sulfurheteroatom may optionally be oxidized. Especially useful are ringscontain one nitrogen combined with one oxygen or sulfur, or two nitrogenheteroatoms. Examples of such heterocyclic groups include piperidinyl,pyrrolyl, pyrrolidinyl, imidazolyl, imidazinyl, imidazolidinyl, pyridyl,pyrazinyl, pyrimidinyl, oxazolyl, oxazolidinyl, isoxazolyl,isoxazolidinyl, thiazolyl, thiazolidinyl, isothiazolyl, homopiperidinyl,homopiperazinyl, pyridazinyl, pyrazolyl, and pyrazolidinyl, mostpreferably thiamorpholinyl, piperazinyl, and morpholinyl.

The term “heteroatom” is used herein to mean an oxygen atom (“O”), asulfur atom (“S”) or a nitrogen atom (“N”). It will be recognized thatwhen the heteroatom is nitrogen, it may form an NR^(a)R^(b) moiety,wherein R^(a) and R^(b) are, independently from one another, hydrogen orC₁₋₄ alkyl, C₂ aminoalkyl, C₁₋₄ halo alkyl, halo benzyl, or R¹ and R²are taken together to form a 5- to 7-member heterocyclic ring optionallyhaving O, S or NR^(C) in said ring, where R^(c) is hydrogen or C₁₋₄alkyl.

The term “heteroaryl” as employed herein refers to groups having 5 to 14ring atoms; 6, 10 or 14 Π electrons shared in a cyclic array; andcontaining carbon atoms and 1, 2, 3 or 4 oxygen, nitrogen or sulfurheteroatoms (where examples of heteroaryl groups are: thienyl,benzo[b]thienyl, naphtho [2,3-b]thienyl, thianthrenyl, furyl, pyranyl,isobenzofuranyl, benzoxazolyl, chromenyl, xanthenyl, phenoxathiinyl,2H-pyrrolyl, pyrrolyl, imidazolyl, pyrazolyl, pyridyl, pyrazinyl,pyrimidinyl, pyridazinyl, indolizinyl, isoindolyl, 3H-indolyl, indolyl,indazolyl, purinyl, 4H-quinolizinyl, isoquinolyl, quinolyl,phthalazinyl, naphthyridinyl, quinazolinyl, cinnolinyl, pteridinyl,4aH-carbazolyl, carbazolyl, β-carbolinyl, phenanthridinyl, acridinyl,perimidinyl, phenanthrolinyl, phenazinyl, isothiazolyl, phenothiazinyl,isoxazolyl, furazanyl and phenoxazinyl groups).

The term “aralkyl” or “arylalkyl” as employed herein by itself or aspart of another group refers to C₁₋₆alkyl groups as discussed abovehaving an aryl substituent, such as benzyl, phenylethyl or2-naphthylmethyl.

The following abbreviations are used throughout the Specification:

BOC: tert-butxoy carbonyl

DMF: dimethylformamide

TBSCl: tert-butyldimethylsilyl chloride

TBAF: tetra-n-butylammonium fluoride

THF: tetrahydrofuran

MsCl: mesyl chloride

TFA: trifluoroacetic acid

Ms: mesyl

DCM: dichloromethane

The present invention is further directed to methods of preparingcompounds of the above Formula I, II or III. The compounds of thisinvention can be prepared by reactions described in schemes 1-8.

Scheme 1 depicts a synthetic route for forming thiophene containingderivatives of Formula I, specifically certain Formula Ia compounds.

The fluorinated PEG stilbenes 12a-d were prepared by reactions shown inscheme 1. To prepare compounds with 2 or 3 ethoxy groups as the PEGlinkage, commercially available chlorides 2a,b were coupled with the OHgroup of 4-methylamino-4′-hydroxy stilbene, 1 (Ono M, et al., Nucl MedBiol. 2003; 30:565-71; Wilson A, et al., J Labelled Cpd Radiopharm.2003; 46:S61) to obtain 3a,b respectively. The free OH groups of 3a,bwere subsequently protected with TBDMSCl to give compounds 7a,b. Toprepare compounds with 4 or 5 ethoxy groups as the PEG linkage, bromides6c,d were separately prepared as shown in scheme 2 and then coupled withstilbene 1 to give TBS protected compounds 7c,d. The O-TBS protectinggroups on compounds 7c,d were removed by treatment of TBAF (1M) in THFto give 3c,d. Compounds 8a-d were obtained by protecting the methylaminogroups of 7a-d with BOC. After removing the TBS protection groups of8a-d with TBAF (1M)/THF, the free OH groups were converted intomesylates by reacting with MsCl in the present of triethylamine to give10a-d. The “cold” fluorinated PEG stilbenes, 12a-d, were successfullyobtained by refluxing 10a-d in anhydrous TBAF/THF (Cox D P, et al., JOrg Chem. 1984; 49:3216-19) followed by stirring with TFA to remove theBOC protection group.

To make the desired ¹⁸F labeled PEG stilbenes, [¹⁸F]12a-d, the N—BOCprotected mesylates 10a-d were employed as the precursors (Scheme 3).Each of the mesylates, 10a-d, was mixed with [¹⁸F]fluoride/potassiumcarbonate and Kryptofix 222 in DMSO and heated at 120° C. for 4 min. Themixture was then treated with aqueous HCl to remove the N—BOC protectinggroup. The crude product was purified by HPLC (radiochemical purity>99%,radiochemical yield 10-30%, decay corrected). The preparation of each¹⁸F labeled compound, [¹⁸F]12a-d, took about 90 min and the specificactivity was estimated to be 900-1,500 Ci/mmol at the end of synthesis.

The syntheses of compounds 15e, 16e and the syntheses of theradiolabeling precursors 15d, 17d for preparing [¹⁸F]15e and [¹⁸F]6e areshown in Scheme 9. To prepare compound 15a, the nitro group of4-nitro-4′-hydroxy stilbene, 13a, was reduced with SnCl₂ in ethanol togive the corresponding amine 14a. The amino group was then treated with(CHO)_(n) and NaBH₃CN to give the dimethylamino compound 15a. Compound15b was obtained by reacting the hydroxyl stilbene, 15a, with bromide20m (which was separately prepared as shown in Scheme 10) and potassiumcarbonate in anhydrous DMF. Compound 15c was obtained by the treatmentof 15b with 1N HCl in acetone. Mono tosylate 15d could be isolated froma product mixture of reacting diol 15c with 1.5 equivalent of tosylchloride in pyridine. The tosylate 15d was converted into floride 15e byrefluxing with anhydrous TBAF in THF. TBAF has to be dried at 58° C.under high vacuum (<0.5 mmHg) for 24 hr before use. The tosyl compound15d was used as the starting material to obtain radio labeled compound[¹⁸F]15e. Nitro compound 13e was similarly synthesized by a couplingreaction of 13a with 20m followed by tosylation and fluorination. Thesynthesis of compound 16e was accomplished by the reduction of the nitrogroup of 13e with SnCl₂/EtOH followed by the monomethylation of theamino group with (CHO)_(n), NaOCH₃ and NaBH₄. An intermediate, 13b, wasreduced to amine, 14c, and then monomethylated to give compound 16c. Toobtain [¹⁸F]16e, N-protected tosylate 17d was designed as the precursorfor radiolabeling, Previously prepared 14a was first monomethylated to16a. The compound 17f was then prepared by coupling of 16a with 20n(Scheme 10) and the introduction of BOC to the 2° amine. Di-tent-butylsiliyl group of 17f was removed with 1N TBAF in THF at room temperatureto give diol 5c, which was monotosylated to yield compound 17d.

A related compound 15h was also synthesized as shown in Scheme 4. Thesubstituted malonate 21 was reduced to diol 22 with DIBALH and thenreacted with one equivalent of TBSCl to give 23. The unprotected OH wasthen converted into bromide 24 with CBr₄/PPh₃. Compound 24 was reactedwith 15a to give 15g which was treated with TBAF to remove TBS group toyield 15h.

Two benzyl derivatives of N,N-dimethyl stilbene, 14 and 15 were alsosynthesized (Scheme 4). Compound 14 was obtained by the reduction of thecorresponding ethyl ester 13³ with LiAlH₄. The benzyl alcohol was thenconverted into the highly reactive benzyl bromide intermediate withHBr/HOAc, which was, without purofication, converted immediately intomethyl ether 15 by the addition of methanol and potassium carbonate.

Those stilbene derivatives with a fluorine atom being directly attachedto the double bond (Formula I: R⁷ or R⁸ is fluorine) were synthesized bywell known methods (e.g. Tetrahedron Lett. 43, (2002), 2877-2879).

To obtain [¹⁸F]15e, precursor 15d was mixed with [¹⁸F]fluoride/potassiumcarbonate and Kryptofix® 222 in DMSO and heated at 120° C. for 4 min.Crude product was purified by HPLC to attain >99% of the radiochemicalpurity with 10% radiochemical yield (decay corrected). The proceduretook 90 min and specific activity was estimated to be 70 Ci/mmol at theend of synthesis. The similar procedure was carried out to obtain[¹⁸F]16e from precursor 17d. After initial reaction in DMSO, the mixturewas treated with aqueous HCl to remove BOC group. Radiochemical puritywas >99% after HPLC purification and the radiochemical yield was 15%.The total synthesis took 110 min and specific activity was estimated tobe 90 Ci/mmol at the end of synthesis.

Some of the compounds are also amenable to microwave synthesis asdescribed below in Examples 50-52.

The radiohalogenated compounds of this invention lend themselves easilyto formation from materials which could be provided to users in kits.Kits for forming the imaging agents can contain, for example, a vialcontaining a physiologically suitable solution of an intermediate ofFormula I, in a concentration and at a pH suitable for optimalcomplexing conditions. The user would add to the vial an appropriatequantity of the radioisotope, and an oxidant, such as hydrogen peroxide.The resulting labeled ligand may then be administered intravenously to apatient, and receptors in the brain imaged by means of measuring thegamma ray or photo emissions therefrom.

When desired, the radioactive diagnostic agent may contain any additivesuch as pH controlling agents (e.g., acids, bases, buffers), stabilizers(e.g., ascorbic acid) or isotonizing agents (e.g., sodium chloride).

The term “pharmaceutically acceptable salt” as used herein refers tothose carboxylate salts or acid addition salts of the compounds of thepresent invention which are, within the scope of sound medicaljudgement, suitable for use in contact with the tissues of patientswithout undue toxicity, irritation, allergic response, and the like,commensurate with a reasonable benefit/risk ratio, and effective fortheir intended use, as well as the zwitterionic forms, where possible,of the compounds of the invention. The term “salts” refers to therelatively nontoxic, inorganic and organic acid addition salts ofcompounds of the present invention. Also included are those saltsderived from non-toxic organic acids such as aliphatic mono anddicarboxylic acids, for example acetic acid, phenyl-substituted alkanoicacids, hydroxy alkanoic and alkanedioic acids, aromatic acids, andaliphatic and aromatic sulfonic acids. These salts can be prepared insitu during the final isolation and purification of the compounds or byseparately reacting the purified compound in its free base form with asuitable organic or inorganic acid and isolating the salt thus formed.Further representative salts include the hydrobromide, hydrochloride,sulfate, bisulfate, nitrate, acetate, oxalate, valerate, oleate,palmitate, stearate, laurate, borate, benzoate, lactate, phosphate,tosylate, citrate, maleate, fumarate, succinate, tartrate, naphthylatemesylate, glucoheptonate, lactiobionate and laurylsulphonate salts,propionate, pivalate, cyclamate, isethionate, and the like. These mayinclude cations based on the alkali and alkaline earth metals, such assodium, lithium, potassium, calcium, magnesium, and the like, as wellas, nontoxic ammonium, quaternary ammonium and amine cations including,but not limited to ammonium, tetramethylammonium, tetraethylammonium,methylamine, dimethylamine, trimethylamine, triethylamine, ethylamine,and the like. (See, for example, Berge S. M., et al., PharmaceuticalSalts, J. Pharm. Sci. 66:1-19 (1977) which is incorporated herein byreference.)

The present invention is also directed at a method of imaging amyloiddeposits. One of the key prerequisites for an in vivo imaging agent ofthe brain is the ability to cross the intact blood-brain barrier after abolus iv injection.

In the first step of the present method of imaging, a labeled compoundof Formula I, II or III is introduced into a tissue or a patient in adetectable quantity. The compound is typically part of a pharmaceuticalcomposition and is administered to the tissue or the patient by methodswell known to those skilled in the art.

For example, the compound can be administered either orally, rectally,parenterally (intravenous, by intramuscularly or subcutaneously),intracisternally, intravaginally, intraperitoneally, intravesically,locally (powders, ointments or drops), or as a buccal or nasal spray.

In a preferred embodiment of the invention, the labeled compound isintroduced into a patient in a detectable quantity and after sufficienttime has passed for the compound to become associated with amyloiddeposits, the labeled compound is detected noninvasively inside thepatient. In another embodiment of the invention, an ¹⁸F labeled compoundof Formula I, II or III is introduced into a patient, sufficient time isallowed for the compound to become associated with amyloid deposits, andthen a sample of tissue from the patient is removed and the labeledcompound in the tissue is detected apart from the patient. In a thirdembodiment of the invention, a tissue sample is removed from a patientand a labeled compound of Formula I, II or III is introduced into thetissue sample. After a sufficient amount of time for the compound tobecome bound to amyloid deposits, the compound is detected.

The administration of the labeled compound to a patient can be by ageneral or local administration route. For example, the labeled compoundmay be administered to the patient such that it is delivered throughoutthe body. Alternatively, the labeled compound can be administered to aspecific organ or tissue of interest. For example, it is desirable tolocate and quantitate amyloid deposits in the brain in order to diagnoseor track the progress of Alzheimer's disease in a patient.

The term “tissue” means a part of a patient's body. Examples of tissuesinclude the brain, heart, liver, blood vessels, and arteries. Adetectable quantity is a quantity of labeled compound necessary to bedetected by the detection method chosen. The amount of a labeledcompound to be introduced into a patient in order to provide fordetection can readily be determined by those skilled in the art. Forexample, increasing amounts of the labeled compound can be given to apatient until the compound is detected by the detection method ofchoice. A label is introduced into the compounds to provide fordetection of the compounds.

The term “patient” means humans and other animals. Those skilled in theart are also familiar with determining the amount of time sufficient fora compound to become associated with amyloid deposits. The amount oftime necessary can easily be determined by introducing a detectableamount of a labeled compound of Formula I, II or III into a patient andthen detecting the labeled compound at various times afteradministration.

The term “associated” means a chemical interaction between the labeledcompound and the amyloid deposit. Examples of associations includecovalent bonds, ionic bonds, hydrophilic-hydrophilic interactions,hydrophobic-hydrophobic interactions, and complexes.

Those skilled in the art are familiar with positron emission tomography(PET) detection of a positron-emitting atom, such as ¹⁸F. The presentinvention is also directed to specific compounds where the ¹⁸F atom isreplaced with a non-radiolabeled fluorine atom.

The radioactive diagnostic agent should have sufficient radioactivityand radioactivity concentration which can assure reliable diagnosis. Thedesired level of radioactivity can be attained by the methods providedherein for preparing compounds of Formula I, II or III.

The imaging of amyloid deposits can also be carried out quantitativelyso that the amount of amyloid deposits can be determined.

Another aspect of the invention is a method of inhibiting amyloid plaqueaggregation. The present invention also provides a method of inhibitingthe aggregation of amyloid proteins to form amyloid deposits, byadministering to a patient an amyloid inhibiting amount of a compound ofthe above Formula I, II or III.

Those skilled in the art are readily able to determine an amyloidinhibiting amount by simply administering a compound of Formula I, II orIII to a patient in increasing amounts until the growth of amyloiddeposits is decreased or stopped. The rate of growth can be assessedusing imaging as described above or by taking a tissue sample from apatient and observing the amyloid deposits therein. The compounds of thepresent invention can be administered to a patient at dosage levels inthe range of about 0.1 to about 1,000 mg per day. For a normal humanadult having a body weight of about 70 kg, a dosage in the range ofabout 0.01 to about 100 mg per kilogram of body weight per day issufficient. The specific dosage used, however, can vary. For example,the dosage can depend on a number of factors including the requirementsof the patient, the severity of the condition being treated, and thepharmacological activity of the compound being used. The determinationof optimum dosages for a particular patient is well known to thoseskilled in the art.

The radioactive diagnostic agent should have sufficient radioactivityand radioactivity concentration which can assure reliable diagnosis. Thedesired level of radioactivity can be attained by the methods providedherein for preparing compounds of Formula I, II or III.

The imaging of amyloid deposits can also be carried out quantitativelyso that the amount of amyloid deposits can be determined.

The following examples are illustrative, but not limiting, of the methodand compositions of the present invention. Other suitable modificationsand adaptations of the variety of conditions and parameters normallyencountered and obvious to those skilled in the art are within thespirit and scope of the invention.

All reagents used in synthesis were commercial products and were usedwithout further purification unless otherwise indicated. ¹H NMR spectrawere obtained on a Bruker DPX spectrometer (200 MHz) in CDCl₃. Chemicalshifts are reported as δ values (parts per million) relative to internalTMS. Coupling constants are reported in hertz. The multiplicity isdefined by s (singlet), d (doublet), t (triplet), br (broad), m(multiplet). Elemental analyses were performed by Atlantic Microlab INC.For each procedure, “standard workup” refers to the following steps:addition of indicated organic solvent, washing the organic layer withwater then brine, separation of the organic layer from the aqueouslayer, drying off the combined the organic layers with anhydrous sodiumsulfate, filtering off the sodium sulfate and removing the organicsolvent under reduced pressure.

Example 12-(2-{4-[2-(4-Methylamino-phenyl)-vinyl]-phenoxy}-ethoxy)-ethanol (3a)

Under the nitrogen atmosphere, 4-methylamino-4′-hydroxy stilbene, 1 (OnoM, et al., Nucl Med Biol. 2003; Wilson A, et al., J Labelled CpdRadiopharm. 2003) (63 mg, 0.28 mmol) and 2a (42 mg, 0.34 mmol) weredissolved in anhydrous DMF (5.0 ml) followed by an addition of potassiumcarbonate (125 mg, 0.91 mmol). The suspension was heated to 100° C. andstirred overnight. After cooled down to room temperature, standardworkup with dichloromethane was applied and the residue was purified bysilica gel preparative TLC (4% methanol in dichloromethane) to affordcompound 3a (67 mg, 76%): ¹H NMR δ 7.37 (m, 4H), 6.89 (m, 4H), 6.63 (d,2H, J=8.48 Hz), 4.16 (t, 2H), 3.88 (t, 2H), 3.78 (t, 2H), 3.68 (t, 2H),2.87 (s, 3H), 2.20 (br, 1H), 1.55 (br, 1H).

Example 22-[-2-(2-{4-[2-(4-Methylamino-phenyl)-vinyl]-phenoxy}-ethoxy)-ethoxy]-ethanol(3b)

Compound 3b was prepared from 1 (150 mg, 0.67 mmol), 2b (136 mg, 0.81mmol), and potassium carbonate (277 mg, 2.01 mmol) in DMF (10 ml) withthe same procedure described for compound 3a. 3b (180 mg, 76%): ¹H NMR δ7.37 (m, 4H), 6.89 (m, 4H), 6.65 (d, 2H, J=8.50 Hz), 4.15 (t, 2H), 3.87(t, 2H), 3.72 (t, 6H), 3.62 (t, 2H), 2.87 (s, 3H), 2.20 (br, 1H), 1.60(b, 1H).

Example 32-{2-[2-(2-{4-[2-(4-Methylamino-phenyl)-vinyl]-phenoxy}-ethoxy)-ethoxy]-ethoxy}-ethanol(3c)

TBAF (1 M in THF, 0.06 ml) was added via a syringe to a solution ofcompound 7c (12 mg, 0.023 mmol) in THF (1 ml). The solution was stirredat room temperature for 2 hours. After standard workup withdichloromethane, the residue was purified by silica gel preparative TLC(4.5% methanol in dichloromethane) to afford 3c (8.7 mg, 94%): ¹H NMR δ7.36 (m, 4H), 6.88 (m, 4H), 6.58 (d, 2H, J=8.5 Hz), 4.15 (t, 2H), 3.86(t, 2H), 3.70 (m, 12H), 2.86 (s, 3H).

Example 42-(2-{2-[2-(2-{4-[2-(4-Methylamino-phenyl)-vinyl]-phenoxy}-ethoxy)-ethoxy]-ethoxy}-ethoxy)-ethanol(3d)

Compound 3d was prepared from 7d (15 mg, 0.027 mmol) and TBAF (1 M inTHF, 0.06 ml) in THF (1 ml), with the same procedure described forcompound 3c. 3d (7.8 mg, 65%): ¹H NMR δ 7.36 (m, 4H), 6.87 (m, 4H), 6.60(d, 2H, J=8.5 Hz), 4.14 (t, 2H), 3.85 (t, 2H), 3.66 (m, 16H), 2.86 (s,3H).

Example 52-(2-{2-[2-(tert-Butyl-dimethyl-silanyloxy)-ethoxy]-ethoxy}-ethoxy)-ethanol(5c)

Tetraethylene glycol, 4c (1.12 g, 5.77 mmol) and TBDMSCl (0.87 g, 5.77mmol) were dissolved in dichloromethane (25 ml) followed by triethylamine (1.46 g, 14.4 mmol). The solution was stirred at room temperaturefor 2 hours. After standard workup with dichloromethane, the residue waspurified by silica gel column chromatography (50% ethyl acetate inhexane) to afford 5c (744 mg, 42%): ¹H NMR δ 3.66 (m, 16H), 2.51 (t, 1H,J=5.86 Hz), 0.89 (s, 9H), 0.07 (s, 6H).

Example 62-[2-(2-{2-[2-(tert-Butyl-dimethyl-silanyloxy)-ethoxy]-ethoxy}-ethoxy)-ethoxy]-ethanol(5d)

Compound 5d was prepared from pentaethylene glycol, 4d (1.13 g, 4.72mmol), TBDMSCl (0.78 g, 5.19 mmol), and triethyl amine (1.2 g, 11.8mmol) in dichloromethane (25 ml) with the same procedure described forcompound 5c. 5d (668 mg, 40%): ¹H NMR δ 3.67 (m, 20H), 2.64 (t, 1H,J=5.63 Hz), 0.89 (s, 9H), 0.06 (s, 6H).

Example 7(2-{2-[2-(2-Bromo-ethoxy)-ethoxy]-ethoxy}-ethoxy)-tert-butyl-dimethyl-silane(6c)

Compound 5c (680 mg, 2.20 mmol) and carbon tetrabromide (947 mg, 2.86mg) were dissolved in dichloromethane (20 ml). The solution was cooleddown to 0° C. with an ice bath and pyridine (2.0 ml) was added followedby triphenylphosphine (749 mg, 0.286 mmol). The solution was stirred at0° C. for half an hour and at room temperature for 2 hours. Afterstandard workup with dichloromethane, the residue was purified by silicagel column chromatography (20% ethyl acetate in hexane) to affordcompound 6c (680 mg, 79.6%): ¹H NMR δ 3.79 (m, 4H), 3.66 (m, 8H), 3.56(t, 2H), 3.47 (t, 2H), 0.89 (s, 9H), 0.07 (s, 6H).

Example 8[2-(2-{2-[2-(2-Bromoethoxy)-ethoxy]-ethoxy}-ethoxy)-ethoxy]-tert-butyl-dimethylsilane(6d)

Compound 6d was prepared from 5d (624 mg, 1.77 mmol), carbontetrabromide (761 mg, 2.30 mmol), triphenylphosphine (602 mg, 2.30mmol), pyridine (2.0 ml) in dichloromethane (20 ml) with the sameprocedure described for compound 6c. 6d (400 mg, 52.3%): ¹H NMR δ 3.79(m, 4H), 3.66 (m, 12H), 3.55 (t, 2H), 3.47 (t, 2H), 0.89 (s, 9H), 0.06(s, 6H).

Example 9{4-[2-(4-{2-[2-(tert-Butyl-dimethyl-silanyloxy)-ethoxy]-ethoxy}-phenyl)-vinyl]-phenyl}-methyl-amine(7a)

Compound 3a (45 mg, 0.14 mmol) and TBDMSCl (33 mg, 0.22 mmol) weredissolved in dichloromethane (10 ml) followed by imidazole (20 mg, 0.29mmol). The solution was stirred at room temperature for 2 hours. Afterstandard workup with dichloromethane, the residue was purified by silicagel column chromatography (1.5% methanol in dichloromethane) to afford7a (56 mg, 91%): ¹H NMR δ 7.40 (m, 4H), 6.90 (m, 4H), 6.75 (d, 2H, J=7.9Hz), 4.15 (t, 2H), 3.88 (t, 2H), 3.82 (t, 2H), 3.66 (t, 2H), 2.85 (s,3H), 0.92 (s, 9H), 0.09 (s, 6H).

Example 10(4-{2-[4-(2-{2-[2-(tert-Butyl-dimethyl-silanyloxy)-ethoxy]-ethoxy}-ethoxy)-phenyl]-vinyl}-phenyl)-methyl-amine(7b)

Compound 7b was prepared from 3b (136 mg, 0.38 mmol), TBDMSCl (86 mg,0.57 mmol), imidazole (52 mg, 0.76 mmol) in dichloromethane (10 ml) withthe same procedure described for compound 7a. 7b (170 mg, 95%): ¹H NMR δ7.37 (m, 4H), 6.88 (m, 4H), 6.66 (d, 2H, J=8.6 Hz), 4.14 (t, 2H), 3.86(t, 2H), 3.75 (m, 6H), 3.57 (t, 2H), 2.88 (s, 3H), 0.90 (s, 9H), 0.07(s, 6H).

Example 11[4-(2-{4-[2-(2-{2-[2-(tert-Butyl-dimethyl-silanyloxy)-ethoxy]-ethoxy}-ethoxy)-ethoxy]-phenyl}-vinyl)-phenyl]-methyl-amine(7c)

Compound 7c was prepared from 1 (98 mg, 0.44 mmol), 6c (210 mg, 0.57mmol), K₂CO3 (300 mg, 2.18 mmol) in DMF (10 ml), with the same proceduredescribed for compound 3a. 7c (213 mg, 95%): ¹H NMR δ 7.36 (m, 4H), 6.87(m, 4H), 6.59 (d, 2H, J=8.5 Hz), 4.14 (t, 2H), 3.86 (t, 2H), 3.75 (m,10H), 3.55 (t, 2H), 2.86 (s, 3H), 0.89 (s, 9H), 0.06 (s, 6H).

Example 12{4-[2-(4-{2-[2-(2-{2-[2-(tert-Butyl-dimethyl-silanyloxy)-ethoxy]-ethoxy}-ethoxy)-ethoxy]-ethoxy}-phenyl)-vinyl]-phenyl}-methyl-amine(7d)

Compound 7d was prepared from 1 (97 mg, 0.43 mmol), 6d (197 mg, 0.47mmol), K₂CO3 (297 mg, 2.15 mmol) in DMF (10 ml), with the same proceduredescribed for compound 3a. 7d (220 mg, 91%): ¹H NMR δ 7.36 (m, 4H), 6.87(m, 4H), 6.59 (d, 2H, J=8.5 Hz), 4.14 (t, 2H), 3.85 (t, 2H), 3.75 (m,14H), 3.55 (t, 2H), 2.86 (s, 3H), 0.89 (s, 9H), 0.06 (s, 6H).

Example 13{4-[2-(4-{2-[2-(tert-Butyl-dimethyl-silanyloxy)-ethoxy]-ethoxy}-phenyl)-vinyl]-phenyl}-methyl-carbamicacid tert-butyl ester (8a)

Under the nitrogen atmosphere, 7a (54 mg, 0.13 mmol) was dissolved inanhydrous THF (5.0 ml) followed by Boc-anhydride (84 mg, 0.25 mmol). Thesolution was refluxed overnight. After standard workup withdichloromethane, the residue was purified by silica gel preparative TLC(2% methanol in dichloromethane) to afford 8a (60 mg, 90%): ¹H NMR δ7.43 (d, 4H, J=8.4 Hz), 7.20 (d, 2H, J=8.4 Hz), 6.97 (q, 2H), 6.90 (d,2H, J=8.7 Hz), 4.14 (t, 2H), 3.87 (t, 2H), 3.80 (t, 2H), 3.64 (t, 2H),3.27 (s, 3H), 1.46 (s, 9H), 0.90 (s, 9H), 0.08 (s, 6H).

Example 14(4-{2-[4-(2-{2-[2-(tert-Butyl-dimethyl-silanyloxy)-ethoxy]-ethoxy}-ethoxy)-phenyl]-vinyl}-phenyl)-methyl-carbamicacid tert-butyl ester (8b)

Compound 8b was prepared from 7b (124 mg, 0.26 mmol) and Boc-anhydride(218 mg, 0.66 mmol) in THF (10 ml), with the same procedure describedfor compound 8a. 8b (130 mg, 86%): ¹H NMR δ 7.43 (d, 4H, J=8.4 Hz), 7.20(d, 2H, J=8.4 Hz), 6.97 (q, 2H), 6.90 (d, 2H, J=8.7 Hz), 4.15 (t, 2H),3.87 (t, 2H), 3.75 (t, 6H), 3.57 (t, 2H), 3.27 (s, 3H), 1.46 (s, 9H),0.90 (s, 9H), 0.07 (s, 6H).

Example 15[4-(2-{4-[2-(2-{2-[2-(tert-Butyl-dimethyl-silanyloxy)-ethoxy]-ethoxy}-ethoxy)-ethoxy]-phenyl}-vinyl)-phenyl]-methyl-carbamicacid tert-butyl ester (8c)

Compound 8c was prepared from 7c (84 mg, 0.16 mmol) and Boc-anhydride(163 mg, 0.49 mmol) in THF (5 ml), with the same procedure described forcompound 8a. 8c (86 mg, 86%): ¹H NMR δ 7.42 (d, 4H, J=7.6 Hz), 7.20 (d,2H, J=8.4 Hz), 6.97 (q, 2H), 6.90 (d, 2H, J=8.7 Hz), 4.15 (t, 2H), 3.87(t, 2H), 3.73 (t, 10H), 3.57 (t, 2H), 3.26 (s, 3H), 1.46 (s, 9H), 0.89(s, 9H), 0.07 (s, 6H).

Example 16{4-[2-(4-{2-[2-(2-{2-[2-(tert-Butyl-dimethyl-silanyloxy)-ethoxy]-ethoxy}-ethoxy)-ethoxy]-ethoxy}-phenyl)-vinyl]-phenyl}-methyl-carbamicacid tert-butyl ester (8d)

Compound 8d was prepared from 7d (210 mg, 0.51 mmol) and Boc-anhydride(840 mg, 2.54 mmol) in THF (10 ml), with the same procedure describedfor compound 8a. 8d (174 mg, 66.7%): ¹H NMR δ 7.42 (d, 4H, J=8.4 Hz),7.20 (d, 2H, J=8.4 Hz), 6.97 (q, 2H), 6.90 (d, 2H, J=8.7 Hz), 4.15 (t,2H), 3.86 (t, 2H), 3.72 (t, 14H), 3.55 (t, 2H), 3.27 (s, 3H), 1.46 (s,9H), 0.89 (s, 9H), 0.06 (s, 6H).

Example 17[4-(2-{4-[2-(2-Hydroxy-ethoxy)-ethoxy]-phenyl}-vinyl)-phenyl]-methyl-carbamicacid tert-butyl ester (9a)

Compound 9a was prepared from 8a (56 mg, 0.11 mmol) and TBAF (1 M inTHF, 0.21 ml) in THF (5 ml), with the same procedure described forcompound 3c. 9a (36 mg, 82%): ¹H NMR δ 7.43 (d, 4H, J=8.4 Hz), 7.20 (d,2H, J=8.4 Hz), 6.97 (q, 2H), 6.90 (d, 2H, J=8.7 Hz), 4.18 (t, 2H), 3.88(t, 2H), 3.78 (t, 2H), 3.68 (t, 2H), 3.27 (s, 3H), 1.46 (s, 9H).

Example 18{4-[2-(4-{2-[2-(2-Hydroxy-ethoxy)-ethoxy]-ethoxy}-phenyl)-vinyl]-phenyl}-methyl-carbamicacid tert-butyl ester (9b)

Compound 9b was prepared from 8b (118 mg, 0.21 mmol) and TBAF (1 M inTHF, 0.42 ml) in THF (10 ml), with the same procedure described forcompound 3c. 9b (94 mg, 99.7%): ¹H NMR δ 7.43 (d, 4H, J=8.4 Hz), 7.20(d, 2H, J=8.4 Hz), 6.97 (q, 2H), 6.90 (d, 2H, J=8.7 Hz), 4.17 (t, 2H),3.87 (t, 2H), 3.74 (t, 6H), 3.62 (t, 2H), 3.27 (s, 3H), 1.46 (s, 9H).

Example 19(4-{2-[4-(2-{2-[2-(2-Hydroxy-ethoxy)-ethoxy]-ethoxy}-ethoxy)-phenyl]-vinyl}-phenyl)-methyl-carbamicacid tert-butyl ester (9c)

Compound 9c was prepared from 8b (66 mg, 0.11 mmol), TBAF (1 M in THF,0.22 ml) and THF (5 ml), with the same procedure described for compound3c. 9c (50 mg, 93.0%): ¹H NMR δ 7.43 (d, 4H, J=8.4 Hz), 7.20 (d, 2H,J=8.4 Hz), 6.97 (q, 2H), 6.90 (d, 2H, J=8.7 Hz), 4.16 (t, 2H), 3.87 (t,2H), 3.78 (t, 10H), 3.61 (t, 2H), 3.27 (s, 3H), 1.46 (s, 9H).

Example 20[4-(2-{4-[2-(2-{2-[2-(2-Hydroxy-ethoxy)-ethoxy]-ethoxy}-ethoxy)-ethoxy]-phenyl}-vinyl)-phenyl]-methyl-carbamicacid tert-butyl ester (9d)

Compound 9d was prepared from 8d (76 mg, 0.12 mmol) and TBAF (1 M inTHF, 0.24 ml) in THF (5 ml), with the same procedure described forcompound 3c. 9d (52 mg, 82.7%): ¹H NMR δ 7.43 (d, 4H, J=8.4 Hz), 7.20(d, 2H, J=8.4 Hz), 6.97 (q, 2H), 6.90 (d, 2H, J=8.7 Hz), 4.16 (t, 2H),3.87 (t, 2H), 3.75 (t, 14H), 3.60 (t, 2H), 3.27 (s, 3H), 1.46 (s, 9H).

Example 21 Methanesulfonic acid2-[2-(4-{2-[4-(tert-butoxycarbonyl-methyl-amino)-phenyl]-vinyl}-phenoxy)-ethoxy]-ethylester(10a)

Compound 9a (36 mg, 0.087 mmol) was dissolved in dichloromethane (5 ml)followed by triethylamine (44 mg, 0.44 mmol). Methanesulfonyl chloride(30 mg, 0.26 mmol) was then added via a syringe. The solution wasstirred at room temperature for 4 hours. After standard workup withdichloromethane, the residue was purified by silica gel preparative TLC(2.0% methanol in dichloromethane) to afford 10a (39 mg, 91%): ¹H NMR δ7.43 (d, 4H, J=8.6 Hz), 7.20 (d, 2H, J=8.4 Hz), 6.98 (q, 2H), 6.89 (d,2H, J=8.6 Hz), 4.41 (m, 2H), 4.16 (m, 2H), 3.87 (m, 4H), 3.27 (s, 3H),3.05 (s, 3H), 1.46 (s, 9H). Anal. (C₂₅H₃₃NO₇S) C. H. N.

Example 22 Methanesulfonic acid2-{2-[2-(4-{2-[4-(tert-butoxycarbonyl-methyl-amino)-phenyl]-vinyl}-phenoxy)-ethoxy]-ethoxy}-ethylester (10b)

Compound 10b was prepared from 9b (81 mg, 0.18 mmol), methanesulfonylchloride (62 mg, 0.54 mmol) and triethylamine (88 mg, 0.88 mmol) indichloromethane (8 ml), with the same procedure described for compound10a. 10b (82 mg, 86.5%): ¹H NMR δ 7.43 (d, 4H, J=8.6 Hz), 7.20 (d, 2H,J=8.4 Hz), 6.97 (q, 2H), 6.90 (d, 2H, J=8.6 Hz), 4.38 (m, 2H), 4.15 (m,2H), 3.85 (m, 2H), 3.76 (m, 6H), 3.27 (s, 3H), 3.05 (s, 3H), 1.46 (s,9H). Anal. (C₂₇H₃₇NO₈S) C. H. N.

Example 23 Methanesulfonic acid2-(2-{2-[2-(4-{2-[4-(tert-butoxycarbonyl-methyl-amino)-phenyl]-vinyl}-phenoxy)-ethoxy]-ethoxy}-ethoxy)-ethylester (10c)

Compound 10c was prepared from 9c (50 mg, 0.10 mmol), methanesulfonylchloride (46 mg, 0.40 mmol) and triethylamine (50 mg, 0.50 mmol) indichloromethane (5 ml), with the same procedure described for compound10a. 10c (56 mg, 96.9%): ¹H NMR δ 7.43 (d, 4H, J=8.6 Hz), 7.20 (d, 2H,J=8.4 Hz), 6.97 (q, 2H), 6.90 (d, 2H, J=8.6 Hz), 4.37 (m, 2H), 4.16 (m,2H), 3.86 (m, 2H), 3.76 (m, 10H), 3.27 (s, 3H), 3.06 (s, 3H), 1.46 (s,9H). Anal. (C₂₉H₄₁NO₉S) C. H. N.

Example 24 Methanesulfonic acid2-[2-(2-{2-[2-(4-{2-[4-(tert-butoxycarbonyl-methyl-amino)-phenyl]-vinyl}-phenoxy)-ethoxy]-ethoxy}-ethoxy]-ethoxy)-ethylester (10d)

Compound 10d was prepared from 9d (58 mg, 0.11 mmol), methanesulfonylchloride (49 mg, 0.43 mmol) and triethylamine (54 mg, 0.54 mmol) indichloromethane (5 ml), with the same procedure described for compound10a. 10d (63 mg, 95%): ¹H NMR δ 7.43 (d, 4H, J=8.6 Hz), 7.20 (d, 2H,J=8.4 Hz), 6.97 (q, 2H), 6.90 (d, 2H, J=8.6 Hz), 4.37 (m, 2H), 4.18 (m,2H), 3.86 (m, 2H), 3.75 (m, 14H), 3.27 (s, 3H), 3.07 (s, 3H), 1.46 (s,9H). Anal. (C₃₁H₄₅NO₁₀S) C. H. N.

Example 25[4-(2-{4-[2-(2-Fluoro-ethoxy)-ethoxy]-phenyl}-vinyl)-phenyl]-methyl-carbamicacid tert-butyl ester (11a)

Anhydrous TBAF (Cox D P, et al., J Org Chem. 1984; 49:3216-19) (38.5 mg0.15 mmol) was added to a solution of compound 10a (14.5 mg, 0.03 mmol)in anhydrous THF (3 ml). The mixture was refluxed for 4 hours. Aftercooled to room temperature, standard workup with dichloromethane wasapplied and the residue was purified by silica gel preparative TLC (2%methanol in dichloromethane) to afford compound 11a (7 mg, 57%): ¹H NMRδ 7.43 (d, 4H, J=8.6 Hz), 7.20 (d, 2H, J=8.4 Hz), 6.97 (q, 2H), 6.91 (d,2H, J=8.6 Hz), 4.60 (d, t, 2H, J1=47 Hz, J2=4.0 Hz), 4.17 (t, 2H), 3.90(t, 3H), 3.75 (t, 1H), 3.27 (s, 3H), 1.46 (s, 9H).

Example 26{4-[2-(4-{2-[2-(2-Fluoro-ethoxy)-ethoxy]-ethoxy}-phenyl)-vinyl]-phenyl}-methyl-carbamicacid tert-butyl ester (11b)

Compound 11b was prepared from 10b (21 mg, 0.04 mmol) and TBAF (52 mg,0.2 mmol) in THF (10 ml), with the same procedure described for compound11a. 11b (17 mg, 94%): ¹H NMR δ 7.43 (d, 4H, J=8.6 Hz), 7.20 (d, 2H,J=8.4 Hz), 6.97 (q, 2H), 6.91 (d, 2H, J=8.6 Hz), 4.58 (d, t, 2H, J1=48Hz, J2=4.0 Hz), 4.16 (t, 2H), 3.85 (t, 3H), 3.74 (t, 5H), 3.26 (s, 3H),1.46 (s, 9H).

Example 27(4-{2-[4-(2-{2-[2-(2-Fluoro-ethoxy)-ethoxy]-ethoxy}-ethoxy)-phenyl]-vinyl}-phenyl)-methyl-carbamicacid tert-butyl ester (11c)

Compound 11c was prepared from 10c (18 mg, 0.03 mmol) and TBAF (42 mg,0.16 mmol) in THF (5 ml), with the same procedure described for compound11a. 11c (12 mg, 77%): ¹H NMR δ 7.43 (d, 4H, J=8.6 Hz), 7.20 (d, 2H,J=8.4 Hz), 6.97 (q, 2H), 6.91 (d, 2H, J=8.6 Hz), 4.67 (t, 1H), 4.55 (d,t, 2H, J1=48 Hz, J2=4.0 Hz), 3.85 (t, 3H), 3.74 (t, 9H), 3.27 (s, 3H),1.46 (s, 9H).

Example 28[4-(2-{4-[2-(2-{2-[2-(2-Fluoro-ethoxy)-ethoxy]-ethoxy}-ethoxy)-ethoxy]-phenyl}-vinyl)-phenyl]-methyl-carbamicacid tert-butyl ester (11d)

Compound 11d was prepared from 10d (15 mg, 0.024 mmol) and TBAF (32 mg,0.12 mmol) in THF (5.0 ml), with the same procedure described forcompound 11a. 11d (11 mg, 84%): ¹H NMR δ 7.43 (d, 4H, J=8.4 Hz), 7.20(d, 2H, J=8.4 Hz), 6.97 (q, 2H), 6.90 (d, 2H, J=8.6 Hz), 4.55 (d, t, 2H,J1=48 Hz, J2=4.0 Hz), 4.15 (t, 2H), 3.86 (t, 3H), 3.72 (t, 13H), 3.26(s, 3H), 1.46 (s, 9H).

Example 29[4-(2-{4-[2-(2-Fluoro-ethoxy)-ethoxy]-phenyl}-vinyl)-phenyl]-methyl-amine(12a)

Trifluoroacetic acid (0.5 ml) was added slowly to a solution of compound11a (7.0 mg, 0.017 mmol) in dichloromethane (1 ml). The mixture was thenstirred at room temperature for 1 hour. After standard workup withdichloromethane, the residue was purified by silica gel preparative TLC(1.0% methanol in dichloromethane) to afford 12a (3 mg, 56%): ¹H NMR δ7.37 (m, 4H), 6.90 (m, 4H), 6.65 (d, 2H, J=8.4 Hz), 4.60 (d, t, 2H,J1=46 Hz, J2=4.0 Hz), 4.17 (t, 2H), 3.90 (t, 3H), 3.76 (t, 1H), 2.88 (s,3H). Anal. (C₁₉H₂₂FNO₂) C. H. N.

Example 30{4-[2-(4-{2-[2-(2-Fluoro-ethoxy)-ethoxy]-ethoxy}-phenyl)-vinyl]-phenyl}-methyl-amine(12b)

Compound 12b was prepared from 11b (17 mg, 0.037 mmol) intrifluoroacetic acid (1 ml) and dichloromethane (2 ml), with the sameprocedure described for compound 12a. 12b (9 mg, 68%): ¹H NMR δ 7.37 (m,4H), 6.88 (m, 4H), 6.64 (d, 2H, J=8.4 Hz), 4.56 (d, t, 2H, J1=46 Hz,J2=4.0 Hz), 4.15 (t, 2H), 3.87 (m, 3H), 3.70 (m, 5H), 2.87 (s, 3H).Anal. (C₂₁H₂₆FNO₃) C. H. N.

Example 31(4-{2-[4-(2-{2-[2-(2-Fluoro-ethoxy)-ethoxy]-ethoxy}-ethoxy)-phenyl]-vinyl}-phenyl)-methyl-amine(12c)

Compound 12c was prepared from 11c (12 mg, 0.024 mmol) intrifluoroacetic acid (0.5 ml) and dichloromethane (1 ml), with the sameprocedure described for compound 12a. 12c (7 mg, 73%): ¹H NMR δ 7.37 (m,4H), 6.89 (m, 4H), 6.62 (d, 2H, J=8.4 Hz), 4.55 (d, t, 2H, J1=46 Hz,J2=4.0 Hz), 4.15 (t, 2H), 3.86 (m, 3H), 3.71 (m, 9H), 2.87 (s, 3H).Anal. (C₂₃H₃₀FNO₄) C. H. N.

Example 32[4-(2-{4-[2-(2-{2-[2-(2-Fluoro-ethoxy)-ethoxy]-ethoxy}-ethoxy)-ethoxy]-phenyl}-vinyl)-phenyl]-methyl-amine(12d)

Compound 12d was prepared from 11d (10 mg, 0.018 mmol) intrifluoroacetic acid (0.3 ml) and dichloromethane (1 ml), with the sameprocedure described for compound 12a. 12d (6 mg, 73%): ¹H NMR δ 7.37 (m,4H), 6.88 (m, 4H), 6.64 (d, 2H, J=8.4 Hz), 4.55 (d, t, 2H, J1=46 Hz,J2=4.0 Hz), 4.14 (t, 2H), 3.87 (m, 3H), 3.70 (m, 13H), 2.87 (s, 3H).Anal. (C₂₅H₃₄FNO₅) C. H. N.

Example 33[¹⁸F][4-(2-{4-[2-(2-Fluoro-ethoxy)-ethoxy]-phenyl}-vinyl)-phenyl]-methyl-amine([¹⁸F]12a)

[¹⁸F]Fluoride, produced by a cyclotron using ¹⁸O(p,n)¹⁸F reaction, waspassed through a Sep-Pak Light QMA cartridge as an aqueous solution in[¹⁸O]-enriched water. The cartridge was dried by airflow, and the ¹⁸Factivity was eluted with 2 mL of Kryptofix 222 (K222)/K₂CO3 solution (22mg of K222 and 4.6 mg of K₂CO₃ in CH₃CN/H₂O 1.77/0.23). The solvent wasremoved at 120° C. under an argon stream. The residue was azeotropicallydried with 1 mL of anhydrous CH₃CN twice at 120° C. under an argonstream. A solution of mesylate precursor 10a (4 mg) in DMSO (0.2 mL) wasadded to the reaction vessel containing the dried ¹⁸F activities. Thesolution was heated at 120° C. for 4 min. Water (2 mL) was added and thesolution was cooled down for 1 min. HCl (10% aq solution, 0.5 mL) wasthen added and the mixture was heated at 120° C. again for 5 min.Aqueous solution of NaOH was added to adjust the pH to basic (pH 8-9).The mixture was extracted with ethyl acetate (1 mL×2) and the combinedorganic layer was dried (Na₂SO₄), and the solvent removed under argonstream with gentle heating (55-60° C.). The residue was dissolved inCH₃CN and injected to HPLC for purification. [Hamilton PRP-1 semi-prepcolumn (7.0×305 mm, 10 μm), CH₃CN/dimethylglutarate buffer (5 mM, pH 7)9/1; Flow rate 2 mL/min]. Retention time of 12a was 8.9 min in this HPLCsystem and well separated from precursor 10a (rt=12 min) as well as thehydrolysis by-product (rt=6.2 min). The preparation took 90 min and theradiochemical yield was 20% (decay corrected). To determineradiochemical purity and specific activity (Spec. Act.), analytical HPLCwas used [Hamilton PRP-1 analytical column (4.1×250 mm, 10 μm),CH₃CN/dimethylglutarate buffer (5 mM, pH 7) 9/1; Flow rate 0.5 mL/min].Retention time of 12a in this system was 10.8 min and RCP was over 99%.Specific activity was estimated by comparing UV peak intensity ofpurified [¹⁸F]10 with reference non-radioactive compound of knownconcentration. The specific activity (Spec. Act.) was 1,000-1,500Ci/mmol after the preparation.

Example 34[¹⁸F]{4-[2-(4-{2-[2-(2-Fluoro-ethoxy)-ethoxy]-ethoxy}-phenyl)-vinyl]-phenyl}-methyl-amine([¹⁸F]12b)

Using a similar reaction [¹⁸F]12b was obtained from 10b. Radiochemicalyield was 30% (decay corrected) and radiochemical purity was >99%. HPLCretention time of 12b was 11.7 min for the analytical system describedabove (Spec. Act.=1,300-1,500 Ci/mmol).

Example 35[¹⁸F][(4-{2-[4-(2-{2-[2-(2-Fluoro-ethoxy)-ethoxy]-ethoxy}-ethoxy)-phenyl]-vinyl}-phenyl)-methyl-amine([¹⁸F]12c)

Using a similar reaction [¹⁸F]12c was obtained from 10c. Radiochemicalyield was 10% (decay corrected) and radiochemical purity was >99%. HPLCretention time of 12c was 11.7 min for the analytical system describedabove (Spec. Act.=900 Ci/mmol).

Example 36[¹⁸F][[4-(2-{4-[2-{2-[2-(2-Fluoro-ethoxy)-ethoxy]-ethoxy}-ethoxy)-ethoxy]-phenyl}-vinyl)-phenyl]-methyl-amine([¹⁸F]12d)

Using a similar reaction [¹⁸F]12d was obtained from 10b. Radiochemicalyield was 20% (decay corrected) and radiochemical purity was >99%. HPLCretention time of 12d was 10.7 min for the analytical system describedabove (Spec. Act.=1,000-1,500 Ci/mmol).

Example 37 4-Amino-4′-hydroxyl stilbene (14a)

Stannous chloride (11.8 g, 0.062 mol) was added to a solution ofcompound 13a (Frinton Lab) (3.0 g, 0.012 mol) in ethanol (100 mL)followed by the addition of concentrated hydrochloric acid (5.0 mL). Thesolution was brought to reflux for 3 hr and cooled to room temperaturestirring overnight. Aqueous sodium hydroxide (1N) was added to adjustthe pH to 8.5-9. After standard workup with dichloromethane, crudeproduct 14a was obtained (2.6 g, ˜100%). The product was used infollowing step without further purifications. ¹H NMR (DMSO-d₆) δ 9.39(s, 1H), 7.30 (d, 2H, J=8.5 Hz), 7.20 (d, 2H, J=8.5 Hz), 6.80 (m, 2H),6.72 (d, 2H, J=8.5 Hz), 6.53 (d, 2H, J=8.5 Hz), 5.19 (s, 2H).

Example 38 4-N,N′-Dimethylamino-4′-hydroxyl stilbene (15a)

To a mixture of 14a (211 mg, 1.0 mmol), paraformaldehyde (300 mg, 10mmol) and sodium cyanoborohydride (189 mg, 3.0 mmol), acetic acid (10mL) was added. The whole mixture was stirred at room temperatureovernight and then poured into 100 mL of water. Sodium carbonate wasadded to adjust the pH to 8-9. After standard workup with 5% methanol indichloromethane, the residue was purified by silica gel columnchromatography (2.5% methanol in dichloromethane) to afford 15a as awhite solid (214 mg, 89.5%): ¹H NMR δ 7.37 (m, 4H), 6.87 (s, 2H), 6.75(m, 4H), 4.68 (s, 1H), 2.98 (s, 6H).

Example 394-N,N′-Dimethylamino-4′-(2,2-dimethyl-[1,3]dioxane-5-ylmethoxy) stilbene(15b)

Under the nitrogen atmosphere, 15a (100 mg, 0.38 mmol) was dissolved inanhydrous DMF (5.0 mL). Potassium carbonate (140 mg, 1.0 mmol) was addedto this solution followed by 5-bromomethyl-2,2-dimethyl-[1,3]dioxane 20m¹ (105 mg, 0.5 mmol). The mixture was heated to 100° C. and stirredovernight. After cooled down to room temperature, standard workup withdichloromethane was applied and the residue was purified by silica gelpreparative TLC (1% methanol in dichloromethane) to afford compound 15b(100 mg, 72%): ¹H NMR δ 7.38 (m, 4H), 6.88 (m, 4H), 6.70 (d, 2H, J=8.7Hz), 4.08 (m, 4H), 3.87 (m, 2H), 2.96 (s, 6H), 2.13 (m, 1H), 1.46 (s,3H), 1.42 (s, 3H). Anal. (C₂₃H₂₉NO₃) C, H, N.

Example 40 4-N,N′-Dimethylamino-4′-(1,3-dihydroxy-propane-2-ylmethoxy)stilbene (15c)

Compound 15b (180 mg, 0.49 mmol) was suspended in acetone (5.0 mL) andcooled to 0° C. with an ice bath. 1N HCl (5.0 mL, 5.0 mmol) was slowlyadded over 20 min. The suspension turned clear solution during theaddition. The solution was stirred at 0° C. for additional half an hourand then warmed to room temperature in half an hour. Saturated sodiumbicarbonate was added to adjust pH to 8.5-9. After standard workup withdichloromethane, the residue was purified by silica gel preparative TLC(5% methanol in dichloromethane) to afford compound 15c as a white solid(140 mg, 87%): ¹H NMR δ 7.40 (m, 4H), 6.88 (m, 4H), 6.74 (m, 2H), 4.10(d, 2H, J=5.47 Hz), 3.89 (d, 4H, J=5.28 Hz), 2.98 (s, 6H), 2.22 (m, 1H).Anal. (C₂₀H₂₅NO₃) C. H. N.

Example 414-N,N′-Dimethylamino-4′-(1-tosyl-3-hydroxy-propane-2-ylmethoxy) stilbene(15d)

Compound 15c (158 mg, 0.49 mmol) was dissolved in anhydrous pyridine (15mL) and cooled to 0° C. with an ice bath. Tosyl chloride (137 mg, 0.72mmol) was added and the solution was stirred at 0° C. for 2 hr. Afterstandard workup with dichloromethane, the residue was purified by silicagel preparative TLC (5% methanol in dichloromethane) to affordmonotosylate compound, 15d, as a white solid (95 mg, 41%): ¹H NMR δ 7.75(d, 2H, J=8.26 Hz), 7.37 (m, 4H), 7.26 (m, 2H), 6.88 (m, 2H), 6.72 (m,4H), 4.26 (d, 2H, J=5.66 Hz), 3.97 (d, 2H, J=5.96 Hz), 3.79 (d, 2H,J=5.24 Hz), 2.95 (s, 6H), 2.38 (m, 4H). Anal. (C₂₇H₃₁NO₅S) C, H, N.

Example 424-N,N′-Dimethylamino-4′-(1-fluoro-3-hydroxy-propane-2-ylmethoxy)stilbene (15e)

Compound 15d (40 mg, 0.083 mmol) was dissolved in anhydrous THF (5.0mL). Under the nitrogen atmosphere, anhydrous TBAF (150 mg, 0.5 mmol) inanhydrous THF (1.0 mL) was slowly added. The solution was then heated toreflux for 3 hr. After cooled down to room temperature, standard workupwith dichloromethane was applied and the residue was applied for silicagel preparative TLC (5% methanol in dichloromethane) to afford product15e (17 mg, 62%): ¹H NMR δ 7.40 (m, 4H), 6.89 (m, 4H), 6.70 (d, 2H,J=8.82 Hz), 4.67 (d d, 2H, J₁=47.1 Hz, J₂=5.46 Hz), 4.10 (d, 2H, J=5.86Hz), 3.88 (d, 2H, J=5.24 Hz), 2.97 (s, 6H), 2.40 (m, 1H), 1.76 (s, 1H).Anal. (C₂₀H₂₄FNO₂) C, H, N.

Example 43 4-Nitro-4′-(2,2-dimethyl-[1,3] dioxane-5-ylmethoxy) stilbene(13b)

Compound 13b was prepared from 13a (241 mg, 1.0 mmol) with the sameprocedure described for compound 15b. 13b (260 mg, 70%): ¹H NMR δ 8.19(d, 2H, J=8.80 Hz), 7.49 (m, 4H), 7.07 (m, 2H), 6.90 (d, 2H, J=8.80 Hz),4.12 (m, 4H), 3.89 (d, 2H), 2.10 (m, 1H), 1.48 (s, 3H), 1.43 (s, 3H).Anal. calcd. (C₂₁H₂₃NO₅) C, H, N.

Example 44 4-Nitro-4′-(1,3-dihydroxy-propane-2-ylmethoxy) stilbene (13c)

Compound 13c was prepared from 13b (260 mg, 0.7 mmol) with the sameprocedure described for compound 15c. 13c (190 mg, 82%): ¹H NMR (CD₃OD)δ 8.19 (d, 2H, J=8.80 Hz), 7.72 (d, 2H, J=8.80 Hz), 7.55 (d, 2H, J=8.70Hz), 7.24 (q, 2H), 6.96 (d, 2H, J=8.70 Hz), 4.09 (d, 2H, J=5.78 Hz),3.74 (d, 4H, J=5.94 Hz), 2.14 (m, 1H). Anal. (C₁₈H₁₉NO₅) C, H, N.

Example 45 4-Nitro-4′-(1-tosyl-3-hydroxy-propane-2-ylmethoxy) stilbene(13d)

Compound 13d was prepared from 13c (80 mg, 0.24 mmol) with the sameprocedure described for compound 15d. 13d (66 mg, 56%): ¹H NMR δ 8.18(d, 2H, J=8.82 Hz), 7.77 (d, 2H, J=8.32 Hz), 7.58 (d, 2H, J=8.82 Hz),7.45 (d, 2H, J=8.73 Hz), 7.28 (d, 2H, J=8.18 Hz), 7.09 (q, 2H), 6.81 (d,2H, J=8.73 Hz), 4.27 (d, 2H, J=5.70 Hz), 4.01 (m, 2H), 3.80 (d, 2H,J=5.61 Hz), 2.40 (m, 4H), 2.02 (s, 1H). Anal. (C₂₅H₂₅NO₇S) C, H, N.

Example 46 4-Nitro-4′-(1-fluoro-3-hydroxy-propane-2-ylmethoxy) stilbene(13e)

Compound 13e was prepared from 13d (33 mg, 0.069 mmol) with the sameprocedure described for compound 15e. 13e (20 mg, 88%): ¹H NMR δ 8.19(d, 2H, J=8.83 Hz), 7.58 (d, 2H, J=8.84 Hz), 7.48 (d, 2H, J=8.74 Hz),7.10 (q, 2H), 6.94 (d, 2H, J=8.68 Hz), 4.69 (d d, 2H, J₁=47.1 Hz,J₂=5.36 Hz), 4.15 (d, 2H, J=5.89 Hz), 3.90 (d, 2H, J=5.43 Hz), 2.43 (m,1H), 1.74 (s, 1H). Anal. (C₁₈H₁₈FNO₄) C, H, N.

Example 47 4-Amino-4′-(1-fluoro-3-hydroxy-propane-2-ylmethoxy) stilbene(14e)

Compound 14e was prepared from 13e (37 mg, 0.11 mmol) with the sameprocedure described for compound 14a. 14e (24 mg, 71%): ¹H NMR δ 7.35(m, 4H), 6.90 (m, 4H), 6.66 (d, 2H, J=8.54 Hz), 4.69 (d d, 2H, J₁=47.1Hz, J₂=5.46 Hz), 4.12 (d, 2H, J=5.84 Hz), 3.90 (d, 2H, J=5.56 Hz), 3.70(s, 2H), 2.39 (m, 1H), 1.71 (s, 1H). Anal. (C₁₈H₂₀FNO₂) C, H, N.

Example 48 4-N-Methyl-amino-4′-(1-fluoro-3-hydroxy-propane-2-ylmethoxy)stilbene (16e)

Under the nitrogen atmosphere, sodium methoxide (22 mg, 0.4 mmol) wasadded to a suspension of compound 14e (24 mg, 0.08 mmol) in methanol (6mL) followed by paraformaldehyde (12 mg, 0.4 mmol). The solution washeated to reflux for 2 hr and cooled to 0° C. with an ice bath. Sodiumborohydride (15 mg, 0.4 mmol) was added in portions. Reaction mixturewas brought to reflux again for 1 hr and poured onto crushed ice. Afterstandard workup with dichloromethane, the residue was applied for silicagel preparative TLC (4.5% methanol in dichloromethane) to afford product16e (23 mg, 92%): ¹H NMR δ 7.37 (m, 4H), 6.87 (m, 4H), 6.59 (d, 2H,J=8.56 Hz), 4.69 (d, d, 2H, J₁=47.1 Hz, J₂=5.44 Hz), 4.12 (d, 2H, J=5.86Hz), 4.00 (s, 1H), 3.89. (d, 2H, J=5.52 Hz), 2.86 (s, 3H), 2.41 (m, 1H),1.75 (s, 1H). Anal. (C₁₉H₂₂FNO₂) C, H, N.

Example 49 4-N-Methyl-amino-4′-hydroxy stilbene (16a)

Compound 16a was prepared from 14a (105 mg, 0.5 mmol) with the sameprocedure as described for compound 16e. 16a (100 mg, 89%): ¹H NMR δ7.34 (m, 4H), 6.86 (s, 2H), 6.79 (d, 2H, J=8.58 Hz), 6.60 (d, 2H, J=8.58Hz), 2.85 (s, 3H).

Example 50 General Microwave Procedure for the Preparation of 12 (n=6,8) Stilbene

Microwave synthesis: The mixture of 16a, alkylating agent (1 eq.), K₂CO₃(3 eq.) in DMF (1 mL/0.05 mmol SB-13) was put in a sealed tube andheated in the microwave oven at the following condition: 180° C., 10min, high absorption level. Solvent was then removed and PTLC[CH₂Cl₂-MeOH (97:3) as developing solvent] gave the desired product(Yield: 42-60% depending on the alkylating agent used).

Example 51(4-(2-(4-(2-(2-(2-(2-(2-(2-Fluoro-ethoxy)-ethoxy)-ethoxy)-ethoxy)-ethoxy)-ethoxy)-phenyl)-vinyl)-phenyl)-methyl-amine(12, n=6)

Yield=60%. ¹H NMR (200 MHz, CDCl₃): δ 7.2-7.5 (4H, m), 6.8-7.0 (4H, m),6.59 (2H, d, J=8.4 Hz), 4.55 (2H, d, t, J₁=46 Hz, J₂=4.0 Hz), 4.14 (2H,t), 3.8-3.9 (3H, m), 3.6-3.8 (17H, m), 2.86 (3H, s). HRMS (EI) m/zcalcd. for [C₂₇H₃₈FNO₆]⁺ 491.2683, found 491.2667.

Example 52(4-(2-(4-(2-(2-(2-(2-(2-(2-(2-(2-Fluoro-ethoxy)-ethoxy)-ethoxy)-ethoxy)-ethoxy)-ethoxy)-ethoxy)-ethoxy)-phenyl)-vinyl)-phenyl)-methyl-amine(12, n=8)

Yield: 42%. ¹H NMR (200 MHz, CDCl₃): δ 7.3-7.5 (4H, m), 6.8-7.0 (4H, m),6.73 (2H, d, J=8.2 Hz), 4.55 (2H, d, t, J₁=46 Hz, J₂=4.0 Hz), 4.14 (2H,t), 3.8-3.9 (3H, m), 3.5-3.8 (25H, m), 2.89 (3H, s). HRMS (EI) m/zcalcd. for [C₃₁H₄₆FNO₈]⁺ 579.3207, found 579.3192.

Example 53 Preparation of Brain Tissue Homogenates

Postmortem brain tissues were obtained from AD patients at autopsy, andneuropathological diagnosis was confirmed by current criteria(NIA-Reagan Institute Consensus Group, 1997). Homogenates were thenprepared from dissected gray matters from AD patients in phosphatebuffered saline (PBS, pH 7.4) at the concentration of approximately 100mg wet tissue/ml (motor-driven glass homogenizer with setting of 6 for30 sec). The homogenates were aliquoted into 1 ml-portions and stored at−70° C. for 6-12 month without loss of binding signal.

Example 54 Binding Studies

As reported previously, [¹²⁵I]IMPY, with 2,200 Ci/mmol specific activityand greater than 95% radiochemical purity, was prepared using thestandard iododestannylation reaction and purified by a simplified C-4mini column (Kung M-P, et al., Euro J Nucl Med Mol Imag. 2004;31:1136-45). Binding assays were carried out in 12×75 mm borosilicateglass tubes. The reaction mixture contained 50 μl of brain homogenates(20-50 μl), 50 μl of [¹²⁵I]IMPY (0.04-0.06 nM diluted in PBS) and 50 μlof inhibitors (10-5-10-10 M diluted serially in PBS containing 0.1%bovine serum albumin, BSA) in a final volume of 1 ml. Nonspecificbinding was defined in the presence of IMPY (600 nM) in the same assaytubes. The mixture was incubated at 37° C. for 2 hr and the bound andthe free radioactivity were separated by vacuum filtration throughWhatman GF/B filters using a Brandel M-24R cell harvester followed by2×3 ml washes of PBS at room temperature. Filters containing the bound¹²⁵I ligand were assayed for radioactivity content in a gamma counter(Packard 5000) with 70% counting efficiency. Under the assay conditions,the specifically bound fraction was less than 15% of the totalradioactivity. The results of inhibition experiments were subjected tononlinear regression analysis using EBDA by which Ki values werecalculated. The results are given in Table 1.

TABLE 1 K_(i) ± SEM K_(i) ± SEM K_(i) ± SEM (nM) (nM) (nM) X = OH X = FIMPY 1.4 ± 0.4* 3a, n = 2 5.2 ± 0.4 12a, n = 2 2.9 ± 0.2 SB-13 1.2 ±0.7* 3b, n = 3 2.8 ± 0.2 12b, n = 3 6.7 ± 0.3 PIB 2.8 ± 0.5⁺ 3c, n = 44.6 ± 0.2 12c, n = 4 4.4. ± 0.8 FMAPO 5.0 ± 1.2⁺ 3d, n = 5 5.2 ± 0.212d, n = 5 6.0 ± 0.8Each value was obtained from three independent measurements performed induplicate.

The fluorinated PEG stilbenes (12a-d) showed excellent bindingaffinities (K_(i)=2.9-6.7 nM); while the corresponding hydroxylsubstitute analogs (3a-d) also displayed very high binding affinities(K_(i)=2.8-5.2 nM) (Table 1). The lipophilicity of this series oflabeled agents, [¹⁸F]12a-d, was within an appropriate range (log P valuewas 2.52, 2.41, 2.05 and 2.28 for n=2-5, respectively). The PEG group iscapable of modulating the molecule size and the distance betweenfluorine atom and the stilbene core structure without affecting Aβplaque-specific binding affinity.

Example 55 Film Autoradiography

Brain sections from AD subjects were obtained by freezing the brain inpowdered dry ice and cut into 20 micrometer-thick sections. The sectionswere incubated with [¹⁸F]tracers (200,000-250,000 cpm/200 μl) for 1 hrat room temperature. The sections were then dipped in saturated Li₂CO3in 40% EtOH (two two-minute washes) and washed with 40% EtOH (onetwo-minute wash) followed by rinsing with water for 30 sec. Afterdrying, the ¹⁸F-labeled sections were exposed to Kodak MR filmovernight.

Example 56 In Vivo Plaque Labeling with [¹⁸F]12b and [¹⁸F]12d

The in vivo evaluation was performed using either double transgenicAPP/PS1 or single transgenic APP2576 mice which were kindly provided byAstraZeneca. After anesthetizing with 1% isoflurane, 250-300 μCi of[¹⁸F]12b or [¹⁸F]12d in 200 μl of 0.1% BSA solution was injected throughthe tail vein. The animals were allowed to recover for 60 min and thenkilled by decapitation. The brains were immediately removed and frozenin powdered dry ice. Sections of 20 micrometers were cut and exposed toKodak MR film for overnight. Ex vivo film autoradiograms were thusobtained.

Example 57 Organ Distribution in Normal Mice

While under isoflurane anesthesia, 0.15 mL of a 0.1% bovine serumalbumin solution containing [¹⁸F]tracers (5-10 μCi) were injecteddirectly into the tail vein of ICR mice (22-25 g, male) The mice (n=3for each time point) were sacrificed by cervical dislocation at 120 minpost injection. The organs of interest were removed and weighed, and theradioactivity was assayed for radioactivity content with an automaticgamma counter. The percentage dose per organ was calculated by acomparison of the tissue counts to suitably diluted aliquots of theinjected material. Total activities of blood were calculated under theassumption that they were 7% of the total body weight. The % dose/g ofsamples was calculated by comparing the sample counts with the count ofthe diluted initial dose.

TABLE 2 Biodistribution in ICR mice after iv injection of [¹⁸F]12a-d in0.1% BSA (% dose/g, avg of 3 mice ± SD) 2 min 30 min 1 hr 2 hr 2A: 12bOrgan Blood 3.14 ± 0.69 2.80 ± 0.44 2.51 ± 0.57 2.03 ± 0.25 Heart 6.25 ±1.79 2.18 ± 0.32 2.13 ± 0.50 1.53 ± 0.08 Muscle 1.06 ± 0.39 1.78 ± 0.341.45 ± 0.26 0.90 ± 0.06 Lung 6.87 ± 1.36 3.20 ± 0.54 3.04 ± 0.96 2.42 ±0.36 Kidney 10.95 ± 2.63  6.31 ± 0.58 5.68 ± 1.24 2.05 ± 1.58 Spleen4.57 ± 1.07 1.81 ± 0.24 1.48 ± 0.91 1.54 ± 0.17 Liver 21.5 ± 4.44 13.0 ±0.72 13.2 ± 2.53 7.20 ± 0.59 Skin 1.18 ± 0.23 2.36 ± 0.29 2.07 ± 0.401.23 ± 0.16 Brain 7.77 ± 1.70 1.59 ± 0.22 1.61 ± 0.39 1.39 ± 0.08 Bone1.43 ± 0.09 1.22 ± 0.17 1.77 ± 0.64 2.74 ± 0.08 2B: 12a, 12c, 12d 12aBlood 2.64 ± 0.55 2.42 ± 0.27 2.04 ± 0.16 2.77 ± 0.63 Brain 8.14 ± 2.033.00 ± 0.16 2.60 ± 0.22 2.14 ± 0.06 Bone 1.89 ± 0.25 1.40 ± 0.11 1.71 ±0.23 2.88 ± 0.07 12c Blood 3.22 ± 0.20 1.88 ± 0.08 1.81 ± 0.48 1.60 ±0.12 Brain 6.59 ± 0.19 1.27 ± 0.03 1.20 ± 0.10 1.21 ± 0.06 Bone 2.31 ±0.12 1.00 ± 0.02 0.98 ± 0.27 1.50 ± 0.05 12d Blood 4.99 ± 0.38 4.66 ±0.06 2.89 ± 0.11 2.59 ± 0.18 Brain 7.30 ± 1.05 2.43 ± 0.03 1.77 ± 0.111.62 ± 0.03 Bone 2.24 ± 0.21 2.29 ± 0.21 1.66 ± 0.01 2.35 ± 0.27

The radioactive compounds, including [¹⁸F]12a-d, penetrated intactblood-brain barrier showing excellent brain uptake in normal mice(6.6-8.1% dose/g brain) at 2 min post iv injection (Table 2A & B). Sincenormal mice were used for the biodistribution experiments, no Aβ plaquesin the brain is expected in these young mice; therefore, the labeledagents, [¹⁸F]12a-d, washed out from the brain quickly (1.2-2.6% dose/gbrain) at 60 min post iv injection. The high initial uptake and rapidwashout in normal mouse brain (with no Aβ plaques in the brain) arehighly desirable properties for Aβ plaque-targeting imaging agents. Thevalues reported in Table 2 are comparable to those reported for [¹¹C]PIBand [¹¹C]SB-13 (Mathis C A, et al., Curr Pharm Des. 2004; 10:1469-92;Ono M, et al., Nucl Med Biol. 2003; Mathis C A, et al., J Med Chem.2003).

A detailed biodistribution of [¹⁸F]12b is shown in Table 2A. It appearsthat at 2 min after injection the compound was taken up in the liver,kidney, lungs and muscle, reflecting a general blood perfusion pattern.The bone uptake at 120 min was high (2.74% dose/g) suggesting there maybe in vivo defluorination. However, the free fluorine are not taken upby brain tissue; therefore, the bone uptake was relatively low. Theother PEG stilbene derivatives, 12a,c,d, showed similar biodistributionpatterns (Table 2B).

Example 58 Partition Coefficient

Partition coefficients were measured by mixing the [¹⁸F]tracer with 3 geach of 1-octanol and buffer (0.1 M phosphate, pH 7.4) in a test tube.The test tube was vortexed for 3 min at room temperature, followed bycentrifugation for 5 min. Two weighed samples (0.5 g each) from the1-octanol and buffer layers were counted in a well counter. Thepartition coefficient was determined by calculating the ratio of cpm/gof 1-octanol to that of buffer. Samples from the 1-octanol layer werere-partitioned until consistent partitions of coefficient values wereobtained (usually the 3rd or 4th partition). The measurement was done intriplicate and repeated three times.

It will be understood to those of ordinary skill in the art that thesame can be performed within a wide and equivalent range of conditions,formulations, and other parameters without affecting the scope of theinvention or any embodiment thereof. All patents, patent applications,and publications cited herein are fully incorporated by reference hereinin their entirety.

What is claimed:
 1. A compound selected from the group consisting of:methanesulfonic acid2-[2-(4-{2-[4-(tert-butoxycarbonyl-methyl-amino)-phenyl]-vinyl}-phenoxy)-ethoxy]-ethylester (10a); methanesulfonic acid2-{2-[2-(4-{2-[4-(tert-butoxycarbonyl-methyl-amino)-phenyl]-vinyl}-phenoxy)-ethoxy]-ethoxy}-ethylester (10b); methanesulfonic acid2-(2-{2-[2-(4-{2-[4-(tert-butoxycarbonyl-methyl-amino)-phenyl]-vinyl}-phenoxy)-ethoxyl]-ethoxy}-ethoxy)-ethylester (10c); and methanesulfonic acid2-[2-(2-{2-[2-(4-{2-[4-(tert-butoxycarbonyl-methyl-amino)-phenyl]-vinyl}-phenoxy)-ethoxy]-ethoxy}-ethoxy]-ethoxy)-ethylester (10d).
 2. A process of making a compound of Formula [¹⁸F] 12:

wherein n=2, 3, 4, or 5, comprising reacting a compound of Formula 10:

with [¹⁸F]F⁻/Krptofix 222 (“K222”) and K₂CO₃, in DMSO and treating theresulting mixture with aqueous HCl.
 3. A compound selected from thegroup consisting of:[4-(2-{4-[2-(2-Hydroxy-ethoxy)-ethoxy]-phenyl}-vinyl)-phenyl]-methyl-carbamicacid tert-butyl ester (9a);{4-[2-(4-{2-[2-(2-Hydroxy-ethoxy)-ethoxy]-ethoxy)-phenyl)-vinyl]-phenyl}-methylcarbamicacid tert-butyl ester (9b);(4-{2-[4-(2-{2-[2-(2-Hydroxy-ethoxy)-ethoxy]-ethoxy}-ethoxy)-phenyl]-vinyl}-phenyl)-methyl-carbamicacid tert-butyl ester (9c); and[4-(2-{4-[2-(2-{2-[2-(2-Hydroxy-ethoxy)-ethoxy]-ethoxy}-ethoxy)-ethoxy]-phenyl)-vinyl)-phenyl]-methyl-carbamicacid tert-butyl ester (9d).
 4. A kit for forming imaging agentscomprising a vial, wherein the vial contains a solution of a compoundthat is methanesulfonic acid2-[2-(4-{2-[4-(tert-butoxycarbonyl-methyl-amino)-phenyl]-vinyl}-phenoxy)-ethoxy]-ethylester (10a); methanesulfonic acid2-{2-[2-(4-{2-[4-(tert-butoxycarbonyl-methyl-amino)-phenyl]-vinyl}-phenoxy)-ethoxy]-ethoxy}-ethylester (10b); methanesulfonic acid2-(2-{2-[2-(4-{2-[4-(tert-butoxycarbonyl-methyl-amino)-phenyl]-vinyl}-phenoxy)-ethoxyl]-ethoxy}-ethoxy)-ethylester (10c); or methanesulfonic acid2-[2-(2-{2-[2-(4-{2-[4-(tert-butoxycarbonyl-methyl-amino)-phenyl]-vinyl}-phenoxy)-ethoxy]-ethoxy}-ethoxy]-ethoxy)-ethylester (10d).